The umami blue is the forward lively sounding model vs the warmer laid back umami red. That said it should not sound thin-
have you verified that the headshell is perfectly level when resting on a stationary LP?
how many hours on the cartridge? give it 25-50 hrs before it starts sounding smoother.
what are your phono preamp load and gain settings?
not saying it will be a warm sounding cart but it should sound better than you describe.