4x5" Astia 100 (not 100F!) weird problem

Figured this deserves its own thread...

What's the main difference between Astia 100 and 100F? I developed a lot of 4x5 sheets in a Jobo drum and FujiHunt Chrome6X kit and Astia 100 was curved, whereas 100F flattened instantly. Basically, Astia 100 sheets retained the semi-circular shape of the Jobo 3010 drum. All expired film, but otherwise no colour cast or any other defects. Anyone else experience this with Astia 100 sheet film?

Differences in the gelatine?

Differences in the drying process? This can make film more curly - too varm and fast drying can make gelatine shrink faster and take the base of the film "with it" when it contracts.

The sheets are curled right out of the drum, after washing, prior to stabilizing, and remain such. They dry fine, but don't flatten by themselves during drying.

old film.