Boolean operation making things invisible

I am trying to import my illustrations from adobe fresco into vectornator to clean them up. the only format that adobe fresco allows me to export while retaining the vector format is pdf.

The import into vectornator goes smoothly and I end up with a lot of small complete shape paths from the vector brush in fresco.

The issue that I am having is when I attempt any of the boolean operations on the paths (for this purpose I’m attempting to unite the small lines together to make all my linework a single shape), all the paths become invisible yet outlined in blue and neither the stroke or fill options do anything to them.

Once I touch away from the lines to deselect them they all disappear and don’t even show up in the layers panel anymore.

I feel like I have tried every solution: opacity, change the stroke size, fill, color, ensure nothing is masked, that i have exactly what i want to unite selected, but it still causes this error.

When I create an illustration from scratch in vectornator I do not have this issue. Only when I import the pdf document from adobe fresco do i have a problem.

I wish to use vectornator over illustrator because it seems to work better and does not charge a monthly fee for use, but adobe fresco is my main illustration platform and I need something that works with it.

I have this same issue when I open an AI file on both my Mac and my iPad. If I try to EXLUDE text from a background everything becomes enviable and the layers disappear.

If I draw everything from within VECTORNATOR then it seems to work fine.

My workflow includes drafting on VECTORWORKS and then exporting to DWG then importing that to ILLUSTRATOR (I have access at work, but not at home)and then exporting to SVG for use with a GLOWFORGE.