The Inovelli switch does not use a capacitor on the high setting, so there is no “doubling up”. I would double-check to insure the pull chain is set to the high setting.
Just checking . . these are connected to only one fan, correct? You’ll get dimished speeds with two or more.
The switch should be putting out 120VAC on high. If you can, using a meter, test across the load and the neutral with the fan running on high (i.e. under load). Ideally this would be at the fan, but that’s pretty hard to do without getting smacked, so test at the switch.