Try to change Audio transitions from Gapless-> None in Options/Playback/Audio.

I do not use the Media Monkey EQ. I turned off the volume leveling and the problem persists.

Did you try the other suggestions?

It does persist after restarting the phone. I have also reset the network connections on the phone and re-paired my speakers with it.

Does this persist after a phone restart? If so, try disabling Level volume and the Equalizer. Does either of those fix the issue?

When playing audio via bluetooth speaker on my Oneplus 12 after a few minutes a bad distortion sound begins playing over the music. I went back and tried it on my old phone and the distortion does not occur. This happens on multiple bluetooth speakers. If I stop playback and start it again the distortion sound stops for a few minutes more then starts again. Oneplus support is telling me that Media Monkey is not compatible with the Oneplus 12.