iOS beta users can install older versions of the app through TestFlight, if needed.
(Warning: Try not to do this unless you really need to. Most new versions contain a number of bugfixes and changes, and you could get into a weird state if you jump around versions frequently.)
- Open the TestFlight app and select byte:
- Scroll down to the Information section and select "Previous builds":
- From here you can scroll through the list of all the beta versions since the beginning. You can install any of these to replace your current version.