In general, if ATC requires you to wait for any extended period of time, the first thing to check is the AI aircraft as they aren't very bright.
Delete all or reduce the number of your AI aircraft. The Gate Hold is because the wind changed, so you're waiting for AI traffic to clear before you can use the newly active runway. If it takes a super long time, check the local map to see if an AI aircraft is stuck somewhere, like the end of the runway.