Upgrade will fail prechecks due to the repo-sync failing between the nodes, or you will see that the repo-sync in your environment is failed while not in an upgrade window and the resolve option does not fix it.
VMware NSX
Some files are not syncing between NSX managers repository.
If you are facing this issue and the "Resolve" workaround doesn't help, then please open a ticket with Broadcom support about this issue, including the following files:
Handling Log Bundles for offline review with Broadcom support
Troubleshooting NSX Upgrades: Do's and Don'ts - https://knowledge.broadcom.com/external/article?articleNumber=410550