@Mikel
This is helpful, thanks.
OK, so the error started occurring after changing timezones on the server to match the client. Typically, the client needs to be adjusted. For example, I had the right time noted on my Windows client, but the timezone was set to Pacific instead of Eastern. Changing the timezone then changed my time - which I then corrected, and this resolved a similar issue.
The server timezone can be set to whatever, but the actual time on the server should be accurate.
Did you verify this is not helpful? Passbolt First Install : The OpenPGP server key defined in the config cannot be used to decrypt