Some tracks sound good and others not so much.This makes me think that the issue is the source material itself unless as was stated the bad tracks are always at the beginning or the end or in the middle of the record which would then indicate a setup issue.
The Bass is prominent and not ’tight’This could be your cartridge picking up secondary vibrations from the bass being transmitted into your room from your speakers with those vibrations being picked up by your stand, turntable and tonearm and then being picked up by the cartridge and resent through your system.
This was an issue I had about a year ago. I was able to mitigate it quite a bit by purchasing some ant-vibration pads. The pads I bought were about a 1/2" thick piece of cork sandwiched between two pieces of rubber. They were somewhere between $10 to $20 for a package of four off of Amazon. Ultimately I ended up with a Townshend Audio Seismic platform. Substantially more than $20 off of eBay but it did eliminate any acoustical issue I was having with my turntable rig.