@suiyu111 i have this problem too.
Problem with mods: "Kerbalism" and "RemoteTech".
At the moment of data transfer of a scientific experiment, the connection is lost.
If the data is not transmitted over the radio channel, then the connection is working, the probe is controlled.
Game version: 1.12.5
Kerbalism 3.17 for KSP 1.8.x to 1.12.x
RemoteTech 1.9.12 Recompiled for KSP 1.12.1
The github.com website states that Kerbalism supports RemoteTech. (https://github.com/Kerbalism/Kerbalism/wiki/Home-~-Mod-Support)
But at the start of the game there is a compatibility warning.
Installed mods:
video of the problem
i have already seen this question on the github: https://github.com/Kerbalism/Kerbalism/issues/823