network controllers disappearing at random

[Boomer-1]

twice now with Dev 3 of networks i've had every controller in my world disappear. when I try to put them back, i get the error message that there's already one (the new message you just added) but there isn't a visible block, but perhaps the sf data is still there, as i have to use the debug fish multiple times on that spot to remove the data, then i can put them back. I don't know what's triggering it, and there's no error in the error reports, but i pulled this from console at the time it happened.

[04:19:06] [Craft Scheduler Thread - 5349 - Slimefun/ERROR]: [Slimefun] An Exception was caught while ticking the Block Tickers Task for Slimefun vDev - 1156
java.util.ConcurrentModificationException: null
at java.util.HashMap$HashIterator.nextNode(HashMap.java:1605) ~[?:?]
at java.util.HashMap$KeyIterator.next(HashMap.java:1628) ~[?:?]
at io.github.thebusybiscuit.slimefun4.implementation.tasks.TickerTask.tickChunk(TickerTask.java:140) ~[Slimefun4-Dev (4).jar:?]
at io.github.thebusybiscuit.slimefun4.implementation.tasks.TickerTask.run(TickerTask.java:110) ~[Slimefun4-Dev (4).jar:?]
at org.bukkit.craftbukkit.v1_20_R3.scheduler.CraftTask.run(CraftTask.java:101) ~[paper-1.20.4.jar:git-Paper-497]
at org.bukkit.craftbukkit.v1_20_R3.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:57) ~[paper-1.20.4.jar:git-Paper-497]
at com.destroystokyo.paper.ServerSchedulerReportingWrapper.run(ServerSchedulerReportingWrapper.java:22) ~[paper-1.20.4.jar:?]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1144) ~[?:?]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:642) ~[?:?]
at java.lang.Thread.run(Thread.java:1583) ~[?:?]