Cannot update or reinstall (ios 27.2)

Hi

iphone 18 pro

ios 27.2

Nextdns wanted to update but 'cannot update'

then tried delete->reinstall but 'cannot install'

restart and force restart did not work

there is ample storage space

sign in and out etc app store did not work

no profiles or dns/vpn stuff is active

all other apps install and update fine, its nextdns only

app store works fine

no restrictions or screentime app install restrictions are active

nextdns install/update works fine om ipad pro m4 ipados27

what. on. earth. is preventing this install?!