Netgear Eax80 slow speed after main router restarts

Something very odd is happening to my extender and I have tested it out with two different ones alrdy same EAX80 model and its the only one that does it. After my main router restarts the extender connects but the speeds drops down to 20-50mpbs when its usually closer to 250ish. If I reset the extender and connect to the main router like it was new it works fine again however if I unplug and replug my main router the samething happens again where the speed drops alot.  The firmware is up todate with the lastest verison 1.0.0.36. Is this happening to anyone else? is there any fix to this I debating to return this back.  I have also toggled between one name as well that does not fix it either.