TB-3 Saving to custom sound bank doesnt save tuning

[Boston Green]

Hi there,

Trying to save a preset with the tuning adjusted to the custom slots and can't seem to get it to save the tuning.

Here's what i'm doing:-

Select preset A01
Press Env Mod
I'm then pressing the top left of the screen (its this setting i'd like saved to the custom slot).
Whilst holding down Env Mod I turn the value dial to custom slot U01 (which get everything blinking)
I then press play to save to the slot.

But the tuning doesnt save ..... what am I doing wrong? TIA