https://wccftech.com/oneplus-7-and-7t-pro-updated-to-latest-oxygenos-march-2020-security-update-better-slow-mo-videos-and-more/

Recently, OnePlus started rolling out a newer version of OxygenOS on the OnePlus 7 and 7 Pro that brought the March 2020 security update along with some other changes including stable slow-motion video recording. However, at the time of release, the other phones from the series like the 7T and 7T Pro were missing.

However, the update is now rolling out for those who own the OnePlus 7T and 7T Pro. The update that the company is currently rolling out brings the same changes. Which is obvious at this point since the devices are a lot more similar than one might think.