Facebook errors that reconnecting won't fix

"Please authenticate your account" when launching a campaign
Facebook has placed a security check on the ad account (error code 31 / subcode 3858385). Your UpHex connection is fine — reconnecting will not clear it. The person who owns that Facebook account must log into their own Facebook, open Meta Ads Manager, find the red "Please authenticate your account" banner at the top, complete Facebook's verification steps, then return to UpHex and launch again. Existing ads keep running.
"Non-Discrimination Policy" message
Meta requires the advertiser to accept its Non-Discrimination Policy directly in Meta Ads Manager (check the banner and the Account Quality page). UpHex can't accept it for you, and reconnecting won't help.
A personal ad account isn't showing up
Facebook does not allow a personal ad account (one not inside a Business Manager) to be used through the "Business Portfolio" connection. Either add that ad account to a Business Manager in Meta Business Settings, or connect using the standard Facebook flow. This is a Meta rule, not a UpHex bug.
When reconnecting is the answer
Reconnect Facebook only when the connection shows expired/invalid, the app was removed from Facebook, the password changed, or you were logged out. If you've already reconnected once and it still fails, don't keep reconnecting — it's one of the Meta-side issues above; contact support.