AC300 fusion kit questions

Just got my 2nd ac300 unit in and waiting on my fusion box, Now Im reading now that when these are tied together there are some issues with grid charging …which is actually an important part of my plans …

  I use a PV priority set to grid charge at 40% set up, I had planned on keeping it somewhat simple just using the 30a combiner plug from bluetti to charge with.
  It will be primarily  running a couple small window AC units right off the inverters thru the day with 2400w of PV input on each unit  , am I correctly understanding that set like this the AC300 many people are seeing ac300 in split phase potentially shut down when the AC grid charge starts ?

As for why I want to even use this as split phase is i have considered replacing my 2 small ac units with a bit larger that would require a 30 amp outlet.

If I am misunderstanding the problem or it wont apply to my set up could someone clarify for me so I dont venture off into a set up that would have issues ? or is this something tha Bluetti has now fixed?

AC300 stand-alone also has a 30A socket for output, but only 25A output, because the rated power of 3kw, 120V output.
The purpose of the dual-firewire is mainly to output 240 V. In the dual-firewire, there is a grid input machine will shut down the AC output for two or three seconds, because the machine needs a little time to detect the phase sequence of the grid, but two or three seconds after the machine will automatically switch the AC back to normal output.