@three_easy_payments, thanks for your informative comment!
I would add for the record that the moving magnet input of the OP’s phono stage provides 5 db less gain than is provided by your VTPH-2A, so he would need a SUT gain of 23 db to bring the signal level at the output of the phono stage to the same point as you have with your 18 db SUT. Which would result in presenting the cartridge with an even lower impedance than the 280 ohms his phono stage presents when its built-in SUTs are used at their lowest gain/highest impedance setting.
Also, although I have no experience with Hana cartridges I’m guessing that the consequences of excessive loading would mainly involve some combination of compromises to dynamics, resolution of detail, and transient response. Which would seem to be pretty much the opposite of the issues the OP has reported. So, again, that reinforces the notion that the root cause of the problem is elsewhere.
Best regards,
-- Al