Hi All.
3 weeks ago I bought the DJI Osmo plus along with most of the available accessories I live in Northern Thailand so it was around 37,000 thai Bhat, I am having various problems with the Osmo, sound Sync to video is one, when using without a mobile attached it goes into record mode and then stops after a few seconds (I find myself walking and talking to nothing)!
I bought the Osmo as a vlogging tool to replace my Canon sx710 which is great apart from no external mic port hence I aquired the Osmo +
When loaded with a mobile and Mic it is heavy to carry around in record possition. Also the record indicator is to small and usless outdoors, it cannot be seen!!!
All in all I am gutted with it and would chearfully sell it taking a loss of 10,000 Thb 200 pounds.

Sorry to read on your unpleasant experience with Osmo+.
In summary, there are three problems.
1. Sound cannot sync to video.
Does this issue happen with internal mic or external mic?
What is the current firmware version?

2. The video recording will stop after a few seconds without mobile phone attaching.
When the mobile phone is attached, will the recording stop after a few seconds?
What is the type of your SD card?

3. The mobile device and mic are too heavy and indicator is useless.
Sorry that we cannot change the indicator design to make it more obvious outdoors at the moment. Please move close to Osmo+ to check the indicator status.
If the mobile device and mic are too heavy, you can try smaller mobile phone and mic. Or put the Osmo+ into base or Tripod and Extension Rod for better shooting experience.