Enter, newline, and down arrow broken on Android

What’s broken?

Using the enter key on Android has some weird behavior: you never get a new line, sometimes you get a space, sometimes it breaks a table, sometimes it shifts the placeholder/ghost text. Similar with the down arrow key: the cursor does not get moved down to the next line.

I can reproduce this on desktop Chrome and Firefox when emulating a mobile device with devtools only if it was emulating the mobile device at page load, and it stays broken after exiting mobile device emulation. Thus I believe this is triggered by some platform-detection by BlockNote rather than any true mobile text-editing bug.

https://github.com/user-attachments/assets/93203953-628a-44d8-b2af-04c7baa06c73

What did you expect to happen?

The enter key and down arrow should insert newlines or move down, respectively.

Steps to reproduce

On Android:

1. Navigate to https://www.blocknotejs.org/demo
2. Focus editor and hit enter

On desktop Chrome/Firefox:

1. Open devtools, emulate a mobile device
2. Navigate to https://www.blocknotejs.org/demo
3. Focus editor and hit enter

BlockNote version

Latest; reproduced on @blocknote/shadcn 0.52, 0.53, 0.54.

Environment

Android 10; desktop Chrome/Firefox on Linux and MacOS in mobile emulation mode

Additional context

No response

Contribution

• I'd be interested in contributing a fix for this issue

Sponsor

• I'm a sponsor and would appreciate if you could look into this sooner than later 💖

Start by reproducing the issue on the BlockNote demo on Android and with desktop browser mobile emulation enabled before page load. Investigate the platform-detection path mentioned in the report and compare Enter and down-arrow behavior in those environments. Done means Enter creates a newline reliably and the down arrow moves the cursor to the next line without affecting tables or placeholder text.