Two AC68U in mesh, one reboot when Android phone roams

[banger]

Evening everyone from UK. I have two RT-AC68U in mesh setup with Roaming Assistant disabled as per recommendation on this forum. Only thing I have that roams between the two routers is an Android Mobile on wifi 5ghz. I have Merlin on the main router and the latest stock on the mesh router. When the phone roams from main router to mesh either the mesh router reboots or the signal just goes down as other devices on the mesh router stop working and it takes about 2-3 minutes for them to come back on and for the phone to acquire the mesh wifi. Would roaming Assistant help in this instance? Any ideas?