In the middle of the debug.log I see lines like:
2021-01-28T02:23:37Z UpdateTip: new best=00000000000000000006ddb5e854505f8b792122b0ac9469c07eb26db414f6fb height=667897 version=0x20006000 log2_work=92.622774 tx=610212544 date='2021-01-27T13:04:14Z' progress=0.999724 cache=439.9MiB(3354911txo)
Followed by bitcoin core initializing itself again:
2021-01-28T02:24:41Z Bitcoin Core version v0.20.1 (release build)
2021-01-28T02:24:41Z Qt 5.9.8 (static), plugin=windows (static)
2021-01-28T02:24:41Z System: Windows 10 (10.0), x86_64-little_endian-llp64
It means Bitcoin Core did not shut down cleanly either. Try to run 0.21.0 again but using -reindex and -rescan together. -rescan will fix your block.dat files in case they are corrupted, while -rescan will update your wallet file with newer transactions in the blockchain that are relevant to it.