Try installing pretendo network on tiramisu while keeping the one on aroma and then, on your wii u, change your environment to Tiramisu and then back to aroma again, because that's what I did and it worked for me!

Did you install both of the special inkay-pretendo.wps and 30_nimble.rpx that are on the #testing-announcements on discord?

make sure you have same mii on tiramisu and aroma.

i never used tiramisu... what is it??