I digged this a bit further.
If your logs are not sent to a log file, use this to extract data from console.
sudo journalctl -u cardano-node.service > block_fail.log
Search for TraceNodeIsLeader, you will fin the slot you missed.
In my case, it’s look like the last KES rotation was the problem. InvalidKesSignatureOCERT
Invalid block b9753272f9a5517042a3617a8881daefdf556fb86d92e750b08b9d5783f4a9fa at slot 24975847: ExtValidationErrorHeader (HeaderProtocolError (HardForkValidationErrFromEra S (S (S (Z (WrapValidationErr {unwrapValidationErr = ChainTransitionError [OverlayFailure (OcertFailure (InvalidKesSignatureOCERT 192 189 3 "Reject"))]}))))))
It’s look like it’s not the first time this happened.
I followed the Coincashew guide and had no error and the KES period was fine on Grafana and gLiveView…
https://www.coincashew.com/coins/overview-ada/guide-how-to-build-a-haskell-stakepool-node#18-1-rotate-pools-kes-keys-updating-the-operational-cert-with-a-new-kes-period
There is a script to test KES Signature before missing a block ?
Thank you 