Wow, I have never see this before on any rom,
Have you tried a factory reset from within Evo-X rom
I found this on youtube
If i was in your situation i would backup my apps and data using Migrate-GPE and save it to a safe place, install ether a Xiaomi.eu or Miui Stock Rom and check that the fingerprint is working correctly, once done.
Re-install Evo-X and again check that the fingerprint is working correctly, then restore my apps with Migrate-GPE, remembering to move the migrate folder to the internal phone memory and re-name the folder to Migrate
as Migrate-GPE can only read from the internal memory and looks for the name "Migrate" only without any spaces or extra characters,
I have found that starting from almost stock normally fixes most issues,
I hope you sort it.