Thanks nostr:nprofile1qqsyvrp9u6p0mfur9dfdru3d853tx9mdjuhkphxuxgfwmryja7zsvhqppemhxue69uhkummn9ekx7mp0qyghwumn8ghj7mn0wd68ytnhd9hx2tc42aswu! nostr:nprofile1qqsfq62n9nn2su3rxealkpymtqskv34gg9dg3d2x2wwkl74za6ep4xsprpmhxue69uhkxatnw3hk6tnxd9shg6npvchxxmmdqy48wumn8ghj7mrwvf5hguewvf6xxttsv9uhxetjwejhytn9w5hkummnw3e8yetvv9uj7vgpjfcsa I can confirm that the keyboard is working on non-compose text fields. It looks like this is a bug in Compose UI framework; or with the keyboard when dealing with Compose text fields.
Discussion
Indeed, it only happens with Compose. But it is a well-known bug in old keyboard implementations like AOSP's default keyboard. Lots of applications have had this issue. And since nobody is updating those old keyboard codebases, I don't think this will be solved anytime soon.