LG V60 MMS won't send on wifi

Recently, I haven't been able to send any MMS messages while connected to wifi, whether it is my home wifi or wifi at work (or any other place for that matter). SMS and other things work; MMS works when I'm not connected to wifi. I have tried configuring APN settings manually but nothing online that I have seen has worked for me. I am currently back on default settings but still can't figure out how to get my MMS to work while I am connected to wifi. MMS had not been working in the past initially, but I changed to a new messaging app (Google Messages) and MMS had been working fine for a while on wifi, before not working again recently.