I'm using Vim 8.1 from homebrew on MacOs 10.14.6. Whenever I exit vim back to the terminal, the first keypress in the terminal afterward results in a beachball and CPU spike to 100%, with terminal listed as "not responding" in Activity Monitor. The spike lasts for 5 to 25 seconds, then the terminal is fine until the next time I exit vim. vim is the only thing that seems to be causing this, so far. This behavior is recent -- this same configuration had been working fine before -- although I have updated vim from homebrew in an attempt to fix the problem.
I'm wondering if there's a network issue somewhere (I'm behind a corporate firewall where the admins change the rules occasionally), or some other interaction betweeen vim and terminal that I'm not accounting for.