GL-AXT1800 Slate AX repeater won't connect to 5G hotspot

This appears to be a bug. Do I post here? Do I send this directly to support at GL-iNet?
Please advise.

I have a new GL-AXT1800 Slate AX router, firmware 4.5.0. It won’t connect to the hotel hotspot Wi-Fi over 5G. I found this out quite by accident when the router shifted from the 2.4 G hotel Wi-Fi to the 5 G Wi-Fi on it’s own. Now I set the Repeater mode to only connect to 2.4 G and all is good.

Symptoms/Findings:
When the router connects to the Hilton Honors network (in an Embassy Suites, if that makes any difference), there is no way to raise the captive login portal. None of the usual tricks work, including turning the VPN off, opening a new web page in hopes of being noticed by the portal and have it show the captive portal login page. etc.

The IP addresses shown on the router’s Internet page are odd when attempting connection to 5G. The third octet of the router’s assigned IP address will be different than the IP address for the DNS server and Gateway. For instance, the router will be at 172.20.3.x while both the DNS Server and Gateway will be at 172.20.1.1.

Forcing the repeater mode back to 2.4 GHz fixes everything without additional input from me. These symptoms are easily repeatable.

Where do I report this bug? Here? Via email to GL.iNet? Please advise.