Now I still use idm. Look at some mediainfo: .ts is 60fps. After using the "ffmpeg .ts -c copy .mp4" command, there may be error message, which becomes 58fps. Use mkvtool doesn't seem to have an error message, but it doesn't seem to match. Have you discussed this issue?
Of course, many of the previously downloaded .mp4 frame rates are not common standards (29.97, 30, 59.94, 60, 23.976). Is it just the model's network settings?