Extreme Performance Issues With Long Notes

This issue respects the following points:

• I have read the FAQ
• I have searched for existing issues
• The issue affects the Notes Android app, neither the Notes server app nor the Nextcloud Android app.

Describe the bug

Editing long notes causes extreme performance issues, where there is noticeable input lag when typing.

This issue only occurs when using plain editing mode and not the rich edit mode. However, using the plain edit mode is a requirement for me, as I can often times experience connection drop outs.

This issue is similar to #2192, however in that issue they mentioned that it occurs when using the rich edit mode. This issue occurs specifically with the plain edit mode.

This is a regression, as previous versions of the notes app did not experience this. Later, I will attempt to determine which version introduced the regression, however I believe it was introduced somewhere in the range of 6-9 months ago (I never bothered to report it at that time).

To reproduce:

1. Create a new note
2. Switch to plain edit mode
3. Type some text (anything works)
4. Select everything and copy it
5. Paste text several times
6. Attempt to type anything
7. Repeat steps 4-6 until there is noticeable input lag while typing.

See attached video for example.

https://github.com/user-attachments/assets/b3bc5ea0-c508-4d1d-b764-1680ebea30c5

Expected behavior

Does not have performance issues with long notes

Notes Android version

4.3.1

Notes server version

4.11.0

Nextcloud Android version

3.30.4

Nextcloud version

29.0.7

Device

OnePlus 9 Pro 5G

Android Version

14

App Store

• Google Play Store
• F-Droid
• Huawei App Gallery

Stacktrace

No response

Start by reproducing the lag in Notes Android 4.3.1 using the reported plain-edit workflow of repeatedly copying and pasting a note, then compare it with rich edit mode. Use the attached video and the behavior on long notes as the baseline; done means typing remains responsive in plain edit mode without regressing rich editing.