Should I have issues opening a ~300MB .azw on a modern system?
Background
Modern Windows 10 system (Ryzen 9 5900HS, 32GB ram) Calibre 6.9, Dedrm 10.0.3
I bought a new Kindle book from Amazon today, and used the "Download and Transfer Via USB" option for my Kindle, same Kindle used for dozens of titles.
Turns out it's pretty large, 300MB, the largest azw book I have.
I added the file to my Calibre and it added as expected. It correctly displays the title as well as the cover thumbnail in the calibre title screen.
However, the file just hangs with "Preparing book for first read, please wait". Have let it run for ~30 minutes with no change. Process seems to be using roughly a 1 core constantly.
Tried importing more smaller AZW books, just downloaded in the same way and had no issues. Have no problem with 200MB-600MB EPUB. Tried to convert the file to EPUB and I saw it hang as well.
I'm unsure if there's something about a large AZW book, or something about this specific AZW book causing my issues.
Attached a debug log, but I don't see any errors captured.
Please let me know what direction to look in.