Import Export Does not work, Windows Desktop App 1.3.15

I tried to export a folder (raw backup JSON) and the zip file is bloated : size over 30 Mb.
And the import took 3 hours, reached 66% then turned into a blank window. I close the window and nothing was imported.

Then I tried to export another bigger folder (raw backup JSON), the app straight up crashed.

It seems that import and export work for small documents only. This is a huge problem for me (or anyone who uses RemNote to study complex topics) because I need to move large documents with many nested Rems between knowledge bases to organize them (imagine 500 pages worth of texts). I can’t keep them in one knowledge base because the app becomes bloated and slow and the search become filled with irrelevant information and the Queue has too many cards about random topics.