Split geometry tool failing with different coordinate systems

Nobody has claimed this yet.

As reported by a user:

I had some issues with the splitting function and found out, that it occurs when working with different coordinate systems in multiple layers.

For example:
I have prepared the following layers:

a polyline in EPSG:31255
a pointlayer A in EPSG:31255
a pointlayer B in EPSG:4326

- When opening the project I can split the line without any problems
- then I record a point in the layer B (4326)
- after that I cannot split the line (31255):
- then I record a point in the layer A (31255)
- after that the splitting is possible again

Somehow the switching between the CRS affects the layer identification.
I’ve shared the project with „support“ and here is a short video:
https://www.loom.com/share/2eb9aab7762e415aa76a872b961ba6a4

Reproduce the sequence with a polyline and point layers in EPSG:31255 and EPSG:4326, recording a point in each layer before attempting to split. Start by tracing the split tool's layer identification and CRS-switching path; done means splitting remains available after recording in the differently projected layer.

Written by the indexing model from the issue text.