Wondering if anyone on this site can help troubleshoot an intermittent brake lock up problem?

My 2001 Chevy Silverado 2500HD Duramax 4x4 ext cab long bed with 233k mi on it has been experiencing intermittent brake lock up at what appears to the rear passenger wheel. It only happens under light braking and never happens under hard braking.

Prior to this I had been getting ABS/Brake warning light that would go away after turning off engine and restarting, but would still show C0262 in the history. This indicated bad ABS module which I replaced but didn’t solve the problem, however it did throw anther code, C0238 which is “wheel speed mismatch”. ( I do have oversized wheels tires but I’ve always had them). This two would go away after turning off engine and restarting but still in history.

My mechanic connected his Scanner and confirmed the front 2 wheel speed sensors are working and show the same speeds as well as the rear speed indication. The ABS module also shows to be good.

We thought maybe the rear brake lines might be partially collapsed or restricted so those, as well as the common flex brake lines were replaced.

Note: A few thousand miles prior this issue I did have all four rotors, calipers, pads and front brake lines replaced because all were in bad shape. Not sure if this might be the issue because it didn’t immediately happen.

Any help much appreciated.