Søren,
Sorry, there was a bug in 3.3.9 that results in your issue. It was fixed last night. It only occurs with focusers that cannot move to absolute positions, but clearly, yours is one of those (given the FOCUS_TIMER_VALUE message).
A work-around for now would be using the nightly build
indilib.org/download.html
I know that the fix is in the latest code, and it may be in the latest nightly build release, but I'm not sure. For sure by tomorrow.
This bug affects all focuser algorithms, not just the experimental one.
Hy
BTW, once things are working for you, I'd love to hear if the new algorithm is an improvement for you. It's still a work-in-progress, though. Make sure you start it up reasonably close to focus (e.g. fine tuning, but not major focus changes). Also, I'd recommend checking the full-field button, and experimenting with the step size.