On a server, two different people have Infusion Pylons set up with Potion Filters filled with the True Invisibility spell effect from Iron's Spells. When both Infusion Pylons are active, only one of the two people is invisible at a time. Once a second, one of the two grabs the effect, then the other does -- repeats each second.

My wild guess is that the Pylons are using a fake player to trigger the spell effect and the spell effect's code will cancel a previous effect on a given player and replace it with the new one for that player. If all of the pylons -- regardless of owner -- use the same fake player id, then these will interact. If this is the case, each Infusion Pylon with a different owner would need to have a unique fake player.

This bug may impact other effects if they do the same clear-and-replace technique. This is just the first case I found.

Pylons do not use fake players, they apply effects the same way that potions do. Not sure what else could cause something like this, I'll take a look.

Just tested with 2 players on an ATM 10 server and it works correctly. Are you on ATM 10 or another pack?

It is ATM10. We each used spell lengthening boosters to get the true invisibility effect up over 60 seconds, then cast it many times into the filter until it was full. Then put the filters into our own pylons in separate chunk-loaded chunks. We both had levers next to our pylons, and linked a Redstone Pen remote to the lever, so we could turn the effect on and off. I had mine active when he first activated his and tested the lever, and he reported he was flickering. So toggling the pylons with a lever (or the remote-controlled lever) might play a part.

The pylon owner is set once when placing it, and doesn't change unless the block is broken and replaced. That is the only criteria used for targeting the effect, nothing else matters. Just to confirm, are you running the server in online or offline mode? This sounds like both players have the same uuid somehow

Definitely online. This is a public server for the members of my discord. Each person placed their own pylon down.

I’ll do some more tests today with a third person. We were seeing the effect indicator in inventory go away the same time we were flickering back into visibility, so it’s not just a visual effect. And mobs would switch between coming at us and wandering away.

As the flight effect — from regular potions — doesn’t have this issue, it perhaps points to the implementation of the Iron’s Spells code as the primary difference for this effect. I’ll try making some other effect from that mod and see how it behaves as well.

It can be easily arranged for you to join this server to see the effect in person, should you want to.

Having the same issue on my dedicated ATM10 server. my problem is with only on true invisibility no Redstone involved.