I think you also created the same thread about your situation somewhere else here on Agon forum. Like I have explained everything to you before in another thread you created. Do not connect using optical digital out of your TV to your MX135 processor as they will degrade the sound by quite a bit.
It's time to ditch your MX135 and get a newer HDMI equipped processor that supports lossless DTS HD Master Audio & Dolby True HD formats found on bluray discs.
If you aren't looking for a HT preamp processor that can support 4K HDR, Dolby Atmos/DTS-X, then you will be better off looking for a used one. There are plenty of options out there that will sound better than your MX135.
I highly recommend looking for a used Classe SSP 800 av preamp processor. This model has been discontinued 2 yrs ago. It was first introduced back in 2008 and discontinued in 2017. This unit originally did retail for $9500 when it was in production and nowaday can be had for around $3k to $3500 used due to lack of supports for 4K, Dolby Atmos, DTS-X. But the SSP 800 does support 1080p video (full HD) as well as those lossless surround sound formats such as DTS HD MA & Dolby True HD found on bluray discs. It has HDMI inputs & outputs.
This Classe SSP 800 will sound way better than your MX135. The sound is superb and phenomenal for both movies and music if you use it as a stereo preamp for music listening assuming you have a good quality front end source components. It even sounds better than the newer McIntosh MX122 & MX150/151 av preamp processors.
The sound was very resolved and highly refined when paired with high end power amps and speakers.
I used to have the Classe SSP 800 in my dedicated reference high end theater room. Highly recommended if you aren't looking for a preamp processor that supports 4K, Dolby Atmos, DTS-X. Again, the SSP 800 does not support 4K video nor Dolby Atmos / DTS-X.