Intermittent connectivity with Flex

I recently received a Flex streaming box. I have constant connectivity issues when I try to use it. This is in the bedroom so we don’t play it often. I tried using it the other day after close to a week of not using it. I could not get a connection. I called and CS reset it. It worked for about 15 minutes. I shut off the tv, and tried it again 3 days later. It keeps dropping internet, but I’m showing 75mb download speed in this room. I hooked up a Roku from another room with no problems. I then grabbed a fire stick. Again I had no problem. I put the Flex back on it, and it’s actually froze again. No error code this time. If I hit the back button or home. I bet it gives me rdk-03117.( I think that’s the right code) I didn’t call because all CS ever wants to do us reset my equipment, and get the kids all upset because they’re tv and games are gone for 10-15 minutes. I have a Motorola modem and a Linksys mesh system with (gig)speed service.