bitcoind - how to find out what is affecting the verificationprogress
The verification progress is an estimate, based on how many transactions have been seen versus known statistics about the transaction rate on the network.

If the latest block timestamp is in the past, the verification progress will be below 1. If the latest block timestamp is in the future, the verification progress will be above 1.

Nothing is wrong by it persistently below 1. It's a side effect of blocks only appearing every 10 minutes.