Hi @ni0h, please check your game version again. The current version is v100.1. You can confirm this in the in-game Settings screen, scroll all the way to the bottom.
I am having the same problem playing on Iphone XR ios 18.5, game app version v100.1-250616-1115. Reinstall the app and downloaded all assets with good network still having the crash problem when hunting in Hunt-a-thon. Hard reset my phone worked only one time to fully complete the hunt, but no luck after that. There is no other app turn on during the hunt on Monster hunter now. Hope this can be fix.
Maybe you need to change your phone… Phones from 6-7 years ago may not be able to handle this game. You need at least 8GB of RAM to avoid game crashes.