Reading this post, the effect seems to be the same, internet seems to keep dropping for all clients on the network intermittently.
Internet Keeps Dropping - Community Support - ZeroTier Discussions
However, unlike that post, rebooting all the clients on my network did not help
My interim solution is to disable zt on my mac client when I don’t need access to my zt network, the network normalizes within a few minutes, without fail.
I hope there is some solution to this