Formula involving df(S) doesn't reliably trigger flows

Reproduction steps:

  • Create a text global > test
  • Create a flow
    • Trigger: Formula > $mu(floor, df(S) / 5)$
    • Action: Formula > $df(S)$
    • Action: Set global var > test

Expected: test global should update with the current Unix time every 5 seconds
Actual: test does not update or updates very rarely, indicating that the flow doesn’t trigger as expected.

Triggering the flow manually sets test as expected.

Looks like a similar issue was reported here. Also, I’m able to reproduce this.