If you have lost your streak because you missed recording a day of activity in the app, you can restore it by manually adding an off-platform session (Please note that this is a Premium Feature). Otherwise, unfortunately we cannot restore a lost streak.
If you have lost your streak despite not having missed a day of activity in Tarteel, try logging out of your account and then logging back in, which usually solves any data synchronization related issues.
If the issue persists, you can use the chat to start a conversation with us and report a bug. Make sure to send us a screenshot of your in-app activity tracker and the details of your account so that we can have a closer look inshAllah.