AC1600 Modem/Router (Model No. C6250) Problems with WIFI

Within the last several months, I have noticed that when in my office (where I have the AC1600 [Model No. C6250] modem/router) I have had difficulty maintaining connections with my iPhone, iPad, and MacBook (i.e., when streaming video, it will go well for about five minutes, but then it will freeze -- it will have full WIFI "bars" but absolutely no data going back and forth). I have another (non-Mac) work laptop that is connected via ethernet cable. I seem to have the most problems when connected to the 5G but have noticed that the problems have continued with using the 2.4G setting. It has been rather annoying and seems to be most prevalent on my iPad. Yesterday, I wiped my iPad and restored it, but the problem has not resolved. I have followed all the instructions the internet (i.e., renewing the lease, forgetting the network, resetting network settings, making sure security settings were correct, etc.) and have seen no results. I don't want to buy a new modem/router, but I think I am going down that road. Ironically, the hardwired laptop never misses a beat. Does anyone have any suggestions on how to possibly fix this?