Not getting guild quests SOLUTION
This only works if you are not the guild leader. If you are the guild leader and not getting guild quests, you are stuck until the devs figure out a way to fix your account.
For everyone else...
Your guild leader will need to kick you from the guild (or you can voluntarily quit) and send out a new invite. Once the 24 hour cooldown has expired, rejoin the guild. If there is a quest underway, you will not see it, but you will see the "waiting" guild quest. When the next one comes, you will be able to participate.