Cannot cut custom stickers

[MrNessuno]

As you can see in the screenshot is impossible to cut an object. The button to do it is also invisible but can be pressed if you tap under the square.
The problem is that telegram doesn't allow to select an object.
I tried with multiple images but same result.
For info: It is possible to create a sticker without cutting an object.

Telegram FOSS: 10.12.0
From F-Droid

[psy0rz]

can confirm this is still an issue in 10.14.3

[pe5ha]

same problem