Issues with blurry text on mobile

[step325]

Hi everyone! I’ve created some videos, but I’m having issues with the text/captions. They look "pixelated" (or grainy). I’m not sure why. I’ve tried searching online but can’t seem to find a solution.

These are my settings for desktop videos:

• Formato: MP4
• Codec video: H.264
• Pixel format: yuv420p
• Risoluzione: 1920 x 1080
• Risoluzione provata: 1280 x 720
• Aspect ratio: 16:9
• FPS: 30
• Bitrate video: 16M
• Max rate: 20M
• Buffer size: 32M
• Preset x264: slow

Comando tipo:
remotion render output.mp4
--codec h264
--pixel-format yuv420p
--video-bitrate 16M
--encoding-max-rate 20M
--encoding-buffer-size 32M
--x264-preset slow

And these are the settings for mobile:

• Formato: MP4
• Codec video: H.264
• Pixel format: yuv420p
• Risoluzione: 1080 x 1350
• Aspect ratio: 4:5
• FPS: 30
• Qualità: CRF 11
• Max rate: 40M
• Buffer size: 80M
• Preset x264: slow

Comand:
remotion render output.mp4
--codec h264
--pixel-format yuv420p
--crf 11
--encoding-max-rate 40M
--encoding-buffer-size 80M
--x264-preset slow

I’m attaching some screenshots of mobile versions. Honestly, I’m stuck and don't know how to fix this.