Yes I'm having the same problem repeatedly as well, White Balance not holding, very frustrating. Shooting on a Canon R5 .CR3 Raw Files, running the latest LRT 6.0.3 and LR CC 11.3 with the latest Adobe DNG Converter 14.3 on an M1 Max MacBook Pro 16-inch 2021 model with Mac O Monterey. Any fixes most welcome, it's eating up hours.

Ok. Please put together a small sequence of 5 raw files and a step by step instruction of how I can reproduce the issue.
Put it in a zip file and send it via wetransfer or fromsmash to support@lrtimelapse.com
I will then look into this.

Okay will do, Thanks Gunther. The strange thing is, after writing this, I restarted, initialised the sequence again and it held the white balance custom settings. However it seems to be dropping the Key frame settings when I adjust Highlights and Shadows in Lightroom. I have watched your tutorial on don't let 'Lightroom mess up your timelapses' and tried using the Curves instead, but still the keyframes are not holding many times. And I'm getting major flicker in a sequence when there is absolutely no exposure change at the night end of a Holygrail shot. It's tough because using 'Highlights and Shadows' gives me the best results in terms of holding exposure latitude with the Raw files. I'll send you a sample sequence. Thanks again, Mark