InDesign 14.0.2 french
Windows 10 x64 Pro 1903 - 18362.239

I need to import 148 PDF with 5 pages into each files.
I prepare 5 frames into the A-master.
CTRL+D from the 1st page to select my files.
For the demo, I use 3 files.

Only the second PDF is imported.
All other PDF are visible in Links panel, but with no pages imported.

If I do an the same import without frames on the A-master, I am able to place 5 pages per ID page. But it's longer, without the same scale, etc.

Please check my video attached.
I attach my 3 PDF of the demo.

I've just test under 13.1.1: the bug is already there :-(
Thanks to my users not to tell me...

I also tried to do the same by duplicating my page with no frames on A-master but on the page itself: same result, only the second PDF is imported.

If I choose 2 pages on each PDF, I got 2 PDF on 3. Better, but not enough (frames on page or A-master).

Last test: import without advance options, so only 1st page is imported.
It worked: I got the 3 first pages imported...

Please help :)