Possibly. Try isolating the Umbrel from the network / use it on a different subnet if you can or stop the second LND instance if you’re able to and see it that helps.
I’m personally not very familliar with Lightning or Bitcoin for that matter so I’m limited in the help I can give but I do recommend having a look at the Umbrel troubleshooting guide if you haven’t already here.
(Official Umbrel Troubleshooting Guide and FAQ)
Additionally, you might find this GitHub issue helpful in resolving the problem.
(RPC services not available · Issue #267 · lightninglabs/lightning-terminal · GitHub)