If you do a connection account with gmail domain and you connect your account by Oauth you have to do in 7 days.
If your accounts are other than @gmail there is no need to do that…
If you don’t want to keep reconnecting, you need to create a custom OAuth application (which is what I did). Just follow the instructions in green, which goes to this link: Connecting to Google services using custom OAuth client
I’ve never had to reauthorise my Gmail & Drive connection. Could you explain what steps you took when you created the connection? Which tutorial or guide did you follow?