Philibert Yes, you can try sending us the Output log file for SLR which is located in C:\Users\%username%\AppData\LocalLow\SLR\SLR\ to support@sexlikereal.com email with a note that it's request from forum.
Otherwise, this only happens with local files, it works with streaming?
If it's just with local files, I don't think it's an issue with the connection. Not sure, if this would help, but it's usually a good idea to check installed codecs. We recommend HEVC, and one of these two: K-Lite or LAV filters.