When you attempt to connect to another user's desktop a dialog is displayed on the Sender desktop asking the logged in user to allow your connection .A user is not allowed to connect to another user's desktop unless they are explicitly allowed/authorized.Either you were not granted access or the dialog timed-out and you were implicityly denied access.
Since you are on an older version of RGS, could you try Remote Boost 20.0.1 or RGS 7.7.2 on sender and receiver to see if issue goes away? You can download RGS 7.7.2 from the HP Software Depot. Perform a search on RGS. You can select the Windows package that has both sender and receiver.
I confirmed that it does not occur in RGS receiver 7.7.0 or later.
Also, in ver 7.5.0, it was possible to avoid it by increasing the value of Settings> Network> Network Timeouts> Dialog. Login authentication at the first connection seems to be short with the default timeout value (15 seconds).
Glad the newer versions are working for you. We made some changes on the receiver side in 7.7 that help with disconnects. This also carried into Remote Boost. The default setting for network timeouts are still at 15 seconds which you can still modify for a longer period if your network connections are slow.
Be alert for scammers posting fake support phone numbers and/or email addresses on the community. If you think you have received a fake HP Support message, please report it to us by clicking on "Flag Post".