If your training was reasonably consistent before and you’ve had some sickness, it’s very possible that you weren’t up to full speed when re-testing using the ramp.
If you feel like you can adjust up, great. That’s sort of built into TR, you don’t have to be a slave to your test result if things are too easy/hard (adjust in a work out with the intensity feature).
I wouldn’t worry too much in your position, having done 2x ramp tests in total. Keep training through a few more blocks and see what happens.
If it becomes a pattern but you still prefer the ramp protocol to 20min test, just adjust up a bit each time and go from there.