That error is due to android 7, not the app. Upgrading is the only way to get rid of it, anything else would turn an insecure device into a massive security hole.
Thunder App
An open-source, cross-platform Lemmy client for iOS and Android.
This community is intended to discuss features and feature suggestions for Thunder; as well as friendly, respectful talks about Lemmy in general.
Please use the GitHub repository linked below to submit bug reports, so keeping track of them is easier, and make sure to search first if you already can find an issue for your report.
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Website: Link
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Google Play: Link
iOS Releases
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TestFlight Beta: Link
Related Communities
Nightly Community: Link
Yes, it’s related with OS model. I searched a bit on StackOverFlow and GitHub, but the articles I came across were too technical. I've already added a link to an issue I found on GitHub about this above.
But at least a warning dialog about this problem can be added to the app. Or the app support for devices under Android 8 can be discontinued directly.
Are you by any chance using Adguard or any user-installed certificates? There could be an issue with Adguard with HTTPS filtering enabled. This is the associated GitHub issue: https://github.com/hjiangsu/thunder/issues/178