Mac mail out of office reply extremely delayed

Hi. I recently updated my OS to Mojave 10.14.1.

The "out of office" rule I have set up does not respond as I would hope. I received this feedback from a staff member:

"Something is strange with your out of office replies. I've noticed the past few trips you've been on that the reply does not come right after I send the email...but once you get back in the office I will get all of the replies at once, but it's when you are already back in the office. So if I sent 7 emails to you over a week when you were out of town, the day you get back I get 7 emails from you saying "you are out of town etc...back on November 11th etc.." but I imagine you want them sent out right after someone emails you while you are out of town so they know. Because the past few times if I didn't know you were out of town I wouldn't have known that you weren't replying to email etc...until you were back in town and then I got all the auto-replies at once. There's probably a setting that is off somewhere and that's making the auto-replies act weird."

I have tried to delete the rule and rewrite it. I have tried leaving my Mac mail open, sending myself an email from my gmail account, and still there is no automatic "out of office" reply.

Any help or advice would be greatly appreciated!