Hello, there. My server has pvp enabled in its server properties but still isn't working when players hit each other. If you need any info to help please ask as I don't know what info to give besides that.
Without knowing what all of those plugins do, I would check Worlds and CustomAreas to see if they're causing it. And while it's not my job to judge your server, that plugin list is not very good. Trying to make a single server support Factions, Prison(I'm guessing, with MineReset), SkyBlock, SkyWars, and MyPlot is going to be very difficult. If 2 players are in a faction together, what prevents them from teaming up in skywars? If they can't kill each other, does the match keep going until one of them kills themself to end the match? What prevents players from claiming faction land on MyPlot, thus preventing other players from placing or breaking blocks in their own plot? That's just a few examples, and I'm sure there are many more problems you could come across. This might be irrelevant to your original question, or it might be the cause of it. Your plugin list is really too large to tell.
I don't think you have looked at the plugins closely. 1. They all work fine together. 2. It's not possible to claim land in Plots on my server with the factions plugin. 3. Matches have timers and the factions plugin doesn't affect matches on my server as I have added a counter. 4. Mine reset doesn't even work as it doesn't reset the mines. 5. I just realized why pvp isn't working, thank you for helping me see my stupidity. The reason I can only hit some players outside of mini games is because they are in my faction. I can hurt them fine in matches. Also I like my server, please don't Diss it XD.