Apps do not function usually on my iPhone

Since switching over to iPhone from android some of my apps are very buggy. My starling bank app in particular often returns a retry error when doing things like money transferring or opening or editing spaces. My hastings DriveScore app doesn’t load my score sometimes greyed out dashes have to go back and forth few times for it to load and Shoppix app which I use often gives error every time I click on a tab. Apple has not found any hardware issues and is becoming very annoying or sometimes unusable for these apps. I have tried also same apps on partners iPhone 15 and the results the same. I’ve always preferred android because of the restrictions on apple devices but was sold on the look of it. I’m interested to know if anybody else having same issues

[Re-Titled by Moderator]