Lineage-23.2-20260810-NIGHTLY-pro1x with August 1st security patch installed smoothly via OTA. MindTheGapps16, and root was maintained.
Changelog:
https://download.lineageos.org/devices/pro1x/changes
Great to hear you found the cause and a way to get the data out. We have in other threads looked for the battery, but AFAIK no perfect match have been found, sadly.
Update:
Battery was the culprit. I have replaced the battery with Xiaomi Mi6 BM39 and my Pro1 has successfully booted to Lineage 🙂
Now I can at least transfer all my data...