I noticed my node was not syncing, and through some debugging on #bitcoin-core-dev it seems like it was caused by running out of disk space which left the node in a desynced state, with the valid chain marked as invalid.

After freeing up some space and doing `reconsiderblock` it fixed it.

Comments from @sipa:

> Ugh. That is bad. Out of disk space should not result in database corruption.

> Database errors propagating up and being interpreted as (permanent) block invalidity was one of the contributing factors to the BDB/LevelDB fork in the 0.7/0.8 transition. 

logs:
```
2022-09-05T00:28:55Z UpdateTip: new best=000000000000000000087e337539b369b19570a88c493725020266387d22dac0 height=752167 version=0x2ce8e004 log2_work=93.70770
7 tx=761139817 date='2022-09-01T15:00:06Z' progress=0.998887 cache=146.8MiB(1101860txo)
2022-09-05T00:28:55Z Fatal LevelDB error: IO error: /home/jb55/.bitcoin/chainstate/2963623.ldb: No space left on device
2022-09-05T00:28:55Z You can use -debug=leveldb to get more complete diagnostic messages
2022-09-05T00:28:55Z *** System error while flushing: Fatal LevelDB error: IO error: /home/jb55/.bitcoin/chainstate/2963623.ldb: No space left on device
2022-09-05T00:28:55Z Error: A fatal internal error occurred, see debug.log for details
2022-09-05T00:28:56Z ERROR: ProcessNewBlock: ActivateBestChain failed (System error while flushing: Fatal LevelDB error: IO error: /home/jb55/.bitcoin/chains
tate/2963623.ldb: No space left on device)
2022-09-05T00:28:56Z ERROR: ConnectBlock: Consensus::CheckTxInputs: 221fa678c5c9953d6cd17e584f05c12ab10ba0f2fc8e8131e266f3f0e9819848, bad-txns-inputs-missing
orspent, CheckTxInputs: inputs missing/spent
2022-09-05T00:28:56Z InvalidChainFound: invalid block=000000000000000000079ba062298aa7cef1888f870c23e303a361c19b097ff8  height=752168  log2_work=93.707719  date=2022-09-01T15:13:42Z
2022-09-05T00:28:56Z InvalidChainFound:  current best=000000000000000000087e337539b369b19570a88c493725020266387d22dac0  height=752167  log2_work=93.707707  date=2022-09-01T15:00:06Z
2022-09-05T00:28:56Z ERROR: ConnectTip: ConnectBlock 000000000000000000079ba062298aa7cef1888f870c23e303a361c19b097ff8 failed, bad-txns-inputs-missingorspent, CheckTxInputs: inputs missing/spent
2022-09-05T00:28:56Z InvalidChainFound: invalid block=000000000000000000079ba062298aa7cef1888f870c23e303a361c19b097ff8  height=752168  log2_work=93.707719  date=2022-09-01T15:13:42Z
2022-09-05T00:28:56Z InvalidChainFound:  current best=000000000000000000087e337539b369b19570a88c493725020266387d22dac0  height=752167  log2_work=93.707707  date=2022-09-01T15:00:06Z
```

/**
         * DIRTY means the CCoinsCacheEntry is potentially different from the
         * version in the parent cache. Failure to mark a coin as DIRTY when
         * it is potentially different from the parent cache will cause a
         * consensus failure, since the coin's state won't get written to the
         * parent when the cache is flushed.
         */
        DIRTY = (1 << 0),
        /**
         * FRESH means the parent cache does not have this coin or that it is a
         * spent coin in the parent cache. If a FRESH coin in the cache is
         * later spent, it can be deleted entirely and doesn't ever need to be
         * flushed to the parent. This is a performance optimization. Marking a
         * coin as FRESH when it exists unspent in the parent cache will cause a
         * consensus failure, since it might not be deleted from the parent
         * when this cache is flushed.
         */
        FRESH = (1 << 1),
    };
    CCoinsCacheEntry() : flags(0) {}