EP500 Pro Split Phase / Gen charge cutover

I have two EP500 Pros in split phase to to fusion box. I am using the Bluetti 30A generator plug to charge them both when running low. When I shut the generator off, the split phase breaks at the fusion box (green lights turn off). This causes the power to drop on one leg. I have to unplug the transfer switch cable to reset. Is there a better way to transition from charging to full UPS mode? Just seems a little hard on things. Thank you.

@bharris I’m sorry I don’t understand your meaning. Could you please some pictures of the connection or take a video?