Repeated popup input Remote Desktop and Gateway Password dialog box problem

The Enter Remote Desktop and Gateway Password dialog box repeatedly pops up when using RDM to connect to Remote Desktop via RD Gateway, and entering the correct password does not pass authentication, but using the Microsoft system's mstsc to connect to the Remote Desktop via RD Gateway is fine. This problem has only occurred in the last two weeks, before using RDM to connect to Remote Desktop via RD Gateway is all right, how can I handle this problem?