Window 10
Shotcut 24.10.29
For the past few updates when using tracks that have multiple audio channels, if you select all tracks, it will not be able to be switched back on individual tracks unless restarted. For some reason, some tracks are also missing certain channels sometimes despite having functioned prior. Other similar software tested the same clips with no issues. During export tracks also are sometimes missing. 5.1 surround selected for audio channels. Files are of MKV format.
I reproduced that.
Your other “sometimes” things I do not reproduce when not changing Properties > Audio > Track, and no context or steps were provided. Basically, lacking more info it must wait until someone who is able to fix it happens upon the same issue unless it was a user operating error. For example, “export tracks also are sometimes missing. 5.1 surround selected” depends on Export > Audio > Channels, which defaults from Settings > Audio Channels, which can change when loading a project.
This is fixed for the next version 24.11
I will investigate further and report back if issues persist. I appreciate the quick work and acknowledgment!