Share your experience!
My xperia xa2 ultra will not start unless i do à force start up every time I nerd to use it, triés reseting to factory settings several fîmes but no résulte, has anyone else had that issue?
Hi @Dom69, sorry to hear about this. 
When you power off the device manually, are you always charging the device, or can you just turn it off manually > not being able to start it before you force a start?
I would recommend that you try and perform a software repair as this will reinstall the latest available software in your device, something that a factory reset does not do. This is done to see if this is caused by the software in the device or not.
As always when resetting the device, all data stored on the internal storage will be deleted, so it's important that you create a backup before you start with the repair.
Let me know if that helps!
Tried it and still same issue
Hi again and sorry to hear that there has been no change. 
In this case the device will need to be examined by a trained technician at an authorized service centre and since service cases are handled locally, due to routines, warranty and so forth varies between markets, I recommend that you get in touch with your Local support team and they will assist you further.
Feel free to keep me posted!