Edit: didn't see the edit about discord until now. I'll do my best to replicate the issue and environment you have in the coming days. I'll let you know if I figured anything.
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Hm...
On the top of my head, it might be because of the linux build. Might be an issue with out implementation, or the version of the Buttplug.io library we are using. Hard to say.
There's just too many possibilities for me to know what's happening without some proper debugging.
Unfortunately, I don't have a physical machine to properly test the Linux build other than a VM, or the toys you mentioned. I also took a look at the code again, but I couldn't find any issue. Like I said though, I would love if you could hop onto our Discord server. Hopefully with your help we can figure out the issue :)