AS Mobile Muffled TX Audio

[N4DES]

I have a AS VHF mobile (D04KKF9PW5AN) recently flashed with Q806 & caller ID and works fine in-band (146-174).
It's programmed with mostly amateur stuff have a few VHF 145.XXX amateur repeaters and recently was told my TX audio was muffled under 145 yet 146 and above it works fine with no complaints of muffled audio.

Is this a typical scenario when taking the radio a little out of band to TX in the 144 MHz area? Are there any minor adjustments in the tools area to clean it up if this a regular occurance without going through the whole alignment procedure.

Thanks
Mark