Are nodes vanishing inside Material Functions for anybody else?

I tried to replicate this error just now. It happened one time, removing 3 out of 9 named reroutes.
I’m running 5.5.4

  • Didn’t break afterwards no matter what I did.
  • Didn’t happen again when creating more material functions (made 5 more, all worked).
  • None of material functions broke when re-opened the engine.
  • None of material functions broke when re-booted my machine.
  • Tried other engine versions, worked every time.
  • Tried several other projects (in different engine versions, all worked).

Anyone has a reliable way of re-producing this each time?