I’m not sure what scope/camera combination you are using. However, for focusing with an NB filter you need much longer exposure times, eg 40 or 45s for an Ha filter. Use bin 2 for both Lum and your NB filter.
Fo setting offsets, when you have good skies and stable temperatures, record the focus point using your Lum filter. Then run autofocus using your an NB filter, eg Ha filter, with the long exposure. Record the focus point. The difference between the two is the offset, eg -10 steps. You should repeat this a few times to ensure repeatbility of the offset; you may need to average your results.
The offset is set in the Filter setup tab of the equipment profile. Recall, that if you set it within the sequnce using the control panel, you’ll need to save the sequence as a profile.
Then repeat the above using your other NB filters.
You’ll need to check the use Lum filter within the Filter setup and enable the option with your equipment profile in the focus section.