When I call support via Ultimate Backup, the NPCs arrive in an absolutely standard uniform, which is in the game. I have already reinstalled everything related to EUP several times, but nothing helps. Maybe someone knows what the problem might be?

Change vanilla backup key to none then UB should override it. UB is a separated plugin therefore it has its own variety of customization and options, yet as far as I remember LSPDFR vanilla keys have higher priority, so you have to either change or completely remove them.