Inversion of openHAB-Dimmer-Channel Using Map Transformation

Hello all,
I have some issues with the map transformation in openHAB 3. My shelly 2.5 shutter switches provide me with a channel representing the shutter position as a dimmer. So, they show me e.g. 100 % for fully opened. But, I’d need them to show 0 % when fully opened. As I didn’t find any configuration to change this behavior I would like to perform a map transformation. Therefore, I put the mapping file “” in the respective transform folder with the following content:

0		=	100
1		=	99
2		=	98
99		=	1
100		=	0

The Map Transformation Binding is doing its job as I tested it with a string channel successfully.
The dimmer value is given in percent so that I also tried to play a bit with the unit formats like testing the argument index “%1$d” or something like that. All without success. Could somebody help me out here? It shouldn’t be too complicated but something I seem to overlook?
The error message in the log file says the following:
2023-02-22 16:15:08.664 [WARN ] [al.profiles.MapTransformationProfile] - Could not transform state '52 %' with function '' and format '%1$d'
In the follwong you see my entries in the item/channel setup:

Thanks in advance!

Hello all,
no ideas on my MAP Transformation? Actually, for my specific problem I found another solution: The Shelly Relais provide in two different channels the dimmer values that I need plus the inverted dimmer values, which is actually pretty handy:

Though, a solution for the MAP transformation would be nice anyways.

Best regards