Sorry, to reproduce the issue and facilitate support, please, share a correct complete example, incl. related choices and settings. So, that we can open it with Kobo Enketo. Your attached file doesn’t pass validation.
Hint. To use the Online validator, you need to temporarily replace _kobomatrix with _group.
Could you have a look already at the previous discussion, see search link above? For ex. Adding skip logic to a matrix question and Skip logic for Question Matrix - #3 by Xiphware.
There is also a Help Center article: Adding Skip Logic to a Matrix Question — KoboToolbox documentation.
