[Bug] Validators seem to propose old batches

[vicsn]

🐛 Bug Report

On mainnet v4.6.4 we often see the warning (20 times per hour on a single validator): "Cannot sign a batch at round A from 'X:5000' — Peer (Y proposed a batch for a previous round (A), latest signed round: B"

However, under normal conditions, a validator should not be rebroadcasting old proposals. We should figure out where the race condition or logic bug is coming from

[kaimast]

It may be caused by the proposal logic being stuck at waiting for signatures even when the BFT round advances.