The message "BlockUntilSyncedToCurrentChain: txindex gets block notifications" is displayed regularly in my debug.log. When these messages appear, I can be sure that lnd the synchronization with the chain can not complete and therefore can not start completely.
This message occurs after the message "txindex thread exit" and can be triggered with a call "bitcoin-cli getrawtransaction xxx". I do not know how to fix it or even determine what state the TX index is in. A restart of Bitcoind does not help.
I am using Bitcoin Core version v0.18.0 (Release Build).