Just added full LP playback

The tonearm on the pro-ject the classic has an effective mass of 13.5 grams, so medium mass. It is not too light for the hana cartridge. I run the EL version on the classic and it sounds great. I do agree, the hardware that comes with the hana’s (aluminum bolts) should be replaced for stainless steel allen head bolts, a bit heavier. The hana only weighs 5 grams. Also, if you read the manual or look at pro-ject’s website for the classic...they do recommend a different counterweight for very light cartridges. However, the counterweight that comes with the table is marginally within acceptable limits for the cartridge. The arm can easily be balanced as is. Also, the hana’s seemingly prefer to be run ass down, from my experience. The cartridge just sounds sweeter this way. Lastly, I would not load the cartridge below 400 ohms. Follow the recommendation for 400 or higher. I load mine anywhere from 400 to 500 ohms which it seems to like. Sometimes sibilance is in the recording itself, dependent on the pressing. I’ve proved this, as I own 5 turntables and the recordings effected with sibilance can be heard on all 5 turntables and cartridge combos. Not to say that both VTF/VTA as well as proper alignment can’t reduce it. It will take experimentation to find out. By the way, the pro-jec the classic is an outstanding turntable for the money. I also own the SB version with the built in speed box. Fremer likes it too.

This is from the Galen Carol audio website:

A tonearm whose effective mass is rated at 10 grams or below is considered low mass (e.g. early SME’s, Grace 747 etc.). A tonearm whose effective mass is rated between 11 and 25 grams is considered moderate mass (e.g. SME 309, IV, IV-Vi, V, Triplanar, Graham). Arms above 25 grams of mass are high mass in nature (Eminent Technology, Dynavector).

From stereophile:

The Hana EL's compliance of 10 x 10–6cm/dyne appeared to perfectly match the effective mass of my SME M2-9 tonearm ($1099), the combination exhibiting a moderate resonance at 9.5Hz. The EL tracked everything on Shure's Era IV Audio Obstacle Course test LP and never seemed to overstimulate the arm or bearings.

SME
Series M2-9 is the standard arm having a pivot-stylus dimension of 233.2 mm (9.18�) and will therefore be the one most frequently used. Typical effective mass 9.5 grams.

This should prove that the 13.5 gram tonearm present on The Classic by pro-ject is Not too light a tonearm for use with the Hana EL/SL cartridge. 
Stereophile observed zero negative effects with the 9.5 gram SME arm and the hana. 

Not to beat a dead horse, but here it is used on the classic sb turntable in the Positive feedback review. 
https://positive-feedback.com/reviews/hardware-reviews/hana-el-moving-coil-cartridge/

I'm going to side bar this a bit, but I have a Nova III phonostage by musical surroundings. Once you get your cartridge dialed in, look into the linear power supply as an upgrade. It really helped to define instruments better, helped with separation and brought more resolution to imaging for me. Expensive for what it is, but worth it. 

Welcome aboard!. Don’t give up, you will get it right, and be glad you did, it’s worth the work.

1st: your preamp. It comes from the factory setup for MM cartridges, it needs to be re-configured for your cartridge’s 0.5mv signal strength and it’s 30 ohm coil impedance.

http://www.musicalsurroundings.com/downloads/products/p2-manual.pdf

gain, chart page 4: 40db from factory for MM, top line 1-8 all off.
try 56db gain, 1 in, 2,3,4 off

load, also preset for MM. 1-7 off, 8 on
try top line, 30 ohm setting, 2,3,4,5,6 on; 7,8 off

Gotta change these settings for both l and r channels, it is a dual mono design.

Now how is it?
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If problem persists: it’s something else to do with your TT/cartridge’s physical setup.

IF it is just the VTA, you can adjust it easily enough, your manual, step 11, pages 10,11

https://www.project-audio.com/wp-content/uploads/2018/03/TheClassic_SB_Superpack-Manual.pdf

Still a problem?

Any TT only beats digital when it is very carefully and correctly set up. There is a lot involved/some tools needed, you received alignment protractor and stylus gauge in the box.

level platter; Alignment of arm; cartridge: overhang distance/two null points alignment/tracking force/anti-skate/azimuth/VTA (vertical tracking angle, which is adjusted by raising and lowering the arm post. rock steady platform to start, if isolation needed, solve that independently.

Who/when Setup?

Factory, store, a friend on site, yourself, someone needs to verify, after it is in place, that all is correct. You will benefit forever by acquiring the needed low cost tools, and skills yourself.

Verify Differences:

Do you have the same music, CD and LP? You mention streaming, I use factory CD, factory LP for comparisons. CD version omits any TT issues: Thus amount/sound of bass, mids, highs are correct, to compare TT to.

I use this excellently recorded music to verify system l/r balance (both l/r volume and lack of any frequency shifting l/r) then compare CD/LP after I carefully set up my TT

https://www.discogs.com/Al-Di-Meola-John-McLaughlin-Paco-De-Lucia-Friday-Night-In-San-Francisco/mast...

Side 2, tracks 2 and 3, all 3 guitarists play. Not only CD to LP comparison, these 2 tracks are a big help with final anti-skate adjustment after all else is correct, listen for distinct l/r guitars and audience vol l/r. more or less anti-skate will effect both l/r and it will make the center guitar less distinct, perhaps a bit off center l or r.

anti-skate: start with what the manual says, but use known music and your ears to refine.

CD version, proves your system is balanced, you will here all 3 guitarists distinctly, strong center, very distinct l and r. Good? Great!

Now, LP version. Hear the sibilants/weak bass problem still? Balance, imaging, as distinct as the CD version? These 2 tracks reveal when it is wrong, and wonderfully when it is right!

I can tell you, my LP version, on my very carefully setup TT (i’m 72, lots of setup experience and all low cost needed tools) beats the CD, certainly no sibilants/weak bass.

Enough Bass: I’m interested in the subtleties of Jazz Bass and drums more than canons, so I use these two:

https://www.discogs.com/Niels-Henning-%C3%98rsted-Pedersen-Sam-Jones-Double-Bass/release/1703343

https://www.discogs.com/Mickey-Hart-Planet-Drum/master/246917

mids, I go to Cassandra Wilson’s voice (another to get both CD/LP versions)

https://www.discogs.com/Cassandra-Wilson-Blue-Light-Til-Dawn/master/40901

Eurythmics, Sade, Kodo Drummers, and the damn 1812 canons.

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