Gmail attachments not being downloaded in mobile data(Works on wifi). What would be the reason? [Factory reset solved the issue. K9 mail was a decent alternative until then]

I can download the same when I use wifi tho.

My phone is a Tecno Spark 8c, running Android 11.

Things I have tried:

1. Checked with different carriers. So it's probably not some block that my carrier has or my private dns settings being weird.
2. Cleared the data of the gmail app and ensured that it has access to media and background data.
3. Searched about the issue and saw people talking about clearing the data of downloads and the download manager. Have done that.
4. Reset the mobile data and app preferences in settings. No change after that too.

Related to this: I use Tachiyomi. Similar to attachments I never could download the extensions from within the app using mobile data(could get it manually from their site, so not an issue with their website). Recently the chapter downloads in the app have also stopped working on mobile data, displays No Network Connection available in the notification(have updated to Mihon).

I think it is some android bug. Or downloads or download manager or some other app having issues. I've disabled some bloatware on my phone and also have restricted background data to some apps.

Has anyone else dealt with a similar bug. Is there any fix for it(other than a full reset, if possible)?

Thanks in advance