Multiplayer broken on different engine versions

I’ve built a some multiplayer gameplay that is current with 4.23.1. The project is primarily blueprints. If I upgrade it to 4.24+ or build the UE4 editor from source(4.23.1 and up) the multiplayer complete breaks. From dropped frames, to unresponsive input, even the base character movement component doesn’t correctly function. I’m at a loss as to how I even debug this or profile it too see if it’s getting hung up somewhere. Would any of you have any idea? At this point I’m willing even to hire some sort of consultant because I’ve invested a lot of time into this project for this to be happening.