You may wish to check your security settings in twitter after it revealed that between November 3, 2014, and January 14, 2019 some accounts using Android didn't have their tweets protected, despite having made that setting.
It seems it affected users if certain account changes were made.
Web or iOS were not affected.
Twitter has resolved the issue, however, users should still check their settings.

We've informed people we know were affected by this issue and have turned "Protect your Tweets" back on for them if it was disabled.

[help.twitter.com...]