Hi @vitalunfolding
Haven’t had a chance to replicate the issue above but as an initial measure try changing array($selectags) to just $selectags in your tags__in parameter. If ACF is already returning an array of tag IDs (which is then stored as such in you $selectags variable) then you shouldn’t need to warp it in another array.
Hope that helps-if not, let me know if not and I’ll try and replicate the issue
Cheers
