I've made all of your suggested adjustments and the iPad wifi connection now appears to be stable. Seems to be a lot of manual settings to work with an iPad, btw iOS 9.3.5, it's an older iPad but most current iOS for the model.
Good to hear and know. Thanks for letting us now. Ya, iOS 9 is getting old now so there maybe some features that don't work well with older iOS. I have an iPhone and iPad as well on 9.
RBK50 v18.104.22.168(WW) Circle Enabled
Additional NG HW: C7800/CM1100/CAX80/CM2000, Orbi CBK40, R7800, R7960P, EX7500/EX7700, XR450 and WNHDE111