I think there is a bug somewhere with the subtitle downloads.
Sometimes, when I’m watching a video and download the subtitle (subscene addon), It will download the last subtitle I downloaded instead of the one I selected. At first, when I was binge watching a show, I thought it came from downloading subtitle with an error in the label (sub for episode 15 labelled as episode 16). But when I started getting subtitle from an unrelated show (but previously watched), I started to believe it’s not coming from the subtitle label.
I guess the bug could be in the addon but I’ve been using it for some time without a problem. And since this only started after I activated the “auto play next video” in the settings, I believe it’s more a OSMC (or KODI) issue.
Any idea how I could work around this? Now, the only solution I have is to download the sub on the computer and put them on the NAS myself.