"Add" Button Disables Mid-Recording

Description
During polygon digitization, "Add" points UI abruptly vanishes to standard view mode. This leaves the unfinished geometry frozen on screen and prevents further edits or saving, forcing a restart.

Environment
Staging/ Production
Production

Application (+ app version, build, operating system)
MM 2025.8.0
iOS (Latest)

Steps to reproduce

1. Open Mergin Maps project.
2. Select a polygon layer and click "Add".
3. Add several points to the polygon by panning the crosshair and tapping the "Add" button.
4. Continue panning the map to position the crosshair for the next point.
5. Observe that, randomly, the crosshair disappear and "Add" button is disabled.

Actual results
"Add Point" button and Crosshair disappear while panning.

Expected results
Be able to add as many points as wanted in a single recording session.

Video
https://github.com/user-attachments/assets/25ee9934-fe36-4bf0-b9c0-852a6917cd3e