Steps to reproduce:

1. Add a video block or open a post that already has one.
2. Tap the gear icon.
3. Toggle the "Play inline" setting to on.
4. Save the post and re-open it.
5. Check to see if the "Play inline" setting is still on.

Result: the "Play inline" setting is off after turning it on and saving then re-opening the post. (24s iOS, 37s Android)

^{Tested with WPiOS 13.9.0.0 TestFlight beta on iPhone 6S iOS 13.2.3 and WPAndroid 13.9-rc-1 on Pixel 3 Android 10.}