You may experience an out of memory error after opening more than 5 RDP sessions.
The error/hanging happens mainly when you are transferring files within the RDP sessions and you are using the PAM mapped drive. The mapped drive file transferring is taking up the available java memory and when an user has multiple PAM sessions opened, some sessions will eventually crash due to the low memory. Also, transferring file using the PAM mapped drive is very slow compared to manually mapped drive.
A workaround to avoid this issue is by not using PAM mapped drive for file transferring. You can transfer files using a manually mapped drive whilst in the RDP session, i.e. map a drive manually thru the File Explorer to the destination drive.