Roku express very flaky connection on SXR30 (orbi pro min 30

The SXR30 has great range on both 2.4g and 5g...so much that my roku express in the bedroom no longer needs a satellite/access point because it gets a good signal....SOMETIMES....and that's the problem  I can see three SSID's that I set up on the SXR...channel 1 is default combined 2.4g/5g which apparently you can't separate (which I think is a design flaw)...I split wireless 2 into separate 2.4g and 5g SSID's.  Everything else is vanilla from a factory reset.  The SXR30 is connected directly to the FIOS ONT and all devices, laptops, desktops can connect and run extremely well through the SXR30....EXCEPT for my roku express.

The roku occasionally sees all three networks....as strong (only one bar is grey) and I can connect wirelessly ...but then it fails to get to the internet.  A laptop connected inches from the roku gets a strong/fast connection on the same SSID.  If I move the roku to another TV closer to the router, it works fine.  While I suspect it's the Roku, not sure how I can get a connection and then not reach the internet.    The other confuser is that I've tested multiple times and sometimes I actually get full connection through the roku.  We aren't talking about a weak signal....a thermostat 10' away connects just fine to the router.  Perhaps it's a protocol issue....I think the roku uses 2.4g B. 

I have a satellite (SKS30) I could install, but given the strength of the router signal, I think a satellite would create a wifi mess given strong signal overlap. 

Any thoughts??