Urgot / Tryndamere ULT interaction bug

Playing as Urgot, any champion you ult gets the 4-second timer for the execute where you can proc it yourself or it procs at the end of the timer if the target is below the threshold. However, it seems that Urgot's ult immediately procs when Tryndamere either is hit by the ult while below threshold, or immediately when he drops below the threshold. This was not the case around 2 patches ago, but for some reason this is now the case. Was this an intended change?

Hard to capture a video of it. Here it is in a nutshell.

Urgot ult any champion below threshhold. Ult only goes off if I reactivate, or if timer expires.

Urgot ult tryndamere. Ult immediately reactivates if he's below threshold or if he falls below during without me telling it to.