Macbook freezes upon waking when connected to VPN

I have a 2019 15" MacBook Pro running OS X Mojave (10.14.6) (company laptop, so can't update yet) and I have a weird problem. When I am connected to the company VPN (via the built-in client, no third party VPNs), and my computer goes to sleep, it often freezes for a few minutes when waking up.

When this happens, upon tapping a key or the track pad the screen wakes up, but the mouse cursor is frozen, and the keyboard does not seem to register any input. The touch bar still works (I can adjust volume, brightness, etc), and if I press Esc then the screen immediately turns off, as though it realized "oh snap, I'm actually still asleep". If I wait 3-5 minutes, it will eventually shake itself out of this stupor and wake up properly.

It also only seems to happen if it goes to sleep for at least a few minutes (so, only on actual sleep, not just display blanking).

This isn't much of an answer, but in truth, the response here is "this is a known issue" (and not officially acknowledged by Apple). I admin macbooks in a 100% remote environment and this issue happens even without the inherent VPN (we use a 3rd party and our own server). In my experience, this issue only happens to my users with models 2016 and above / touchbar macbook pros.

Also, there's a similar post... with no definite answer also. Just wanted to point out you're definitely not alone.