IOS 11 Internet Issues

Since I updated my iPad Pro 9.7 and my iPhone 6 to IOS 11 both occasionally lose Internet access when connected to my home network (Zoom Cable Modem/Wifi router; SuddenLink ISP). The devices are connected to the wifi but Internet dependent applications are slow to respond or do not respond at all. The only way I can fix the issues is to restart the modem but that only solves the issue temporarily. My wife's two devices (iPhone 6 and iPad Air mini) have not been updated to IOS 11 and do not have the issue. I was out of town last week and did not encounter the issue when connected to a different wifi router so I am wondering if ISO11 has some incompatibility issues with certain routers/cable modems and if there is a fix for this. I also reset the network setting on the IPad which did not correct the issue. Both devices have plenty of memory. Any suggestions?