For as long as keychain has remained available on mobile, it has never worked for me on the various mobile devices I have had. So I think you may be on to something here. I live in "Mexico".
I used to just use hivesigner for accessing these websites but now neither is available. I can still stake and unstable using peaked but it doesn't always show my 2nd layer tokens either.
You might try a VPN then. Set it to a US node and see if it changes anything. There are free VPNs available, like Brave browser has a built in one.