Same problem. Purchased from Adorama in US in May, 2018, so an early unit. Precision Camera, Sony's US warranty contractor ultimately replaced the image sensor and image stabilizer. Sony's repair line is combative when you contact them. I was asked if I had dropped it, etc. They individual said he had only seen this problem with a camera that someone in their area dropped during cleaning. It felt like they were trying to get me to say something to get them out of their responsibility to fix their (apparently known) manufacturing defect.
The first time I sent the camera to Precision Camera, it came back having had only the sensor cleaned. The second time, initial Sony repair person was also combative, "Did it work when you got it back?" suggesting by his tone that I had broken a camera that had been properly repaired the first time. They seem more concerned about avoiding responsibility than fixing the problem. You never hear from Sony, "I'm sorry for your problem and inconvenience, lets see what we can do to make it right." Sony is more concerned with their 'Policy' than customer satisfaction (you hear 'policy' a lot in a conversation with them). Their customer service representative even said that replacement isn't covered under warranty - only repair (the US warranty DOES list replacement as one option Sony may choose to resolve the problem). It's best to ask the repair line to escalate you to customer service, they are slightly less combative and slightly more helpful.
Sony is pretty hands off with the Precision Camera interaction, and Precision Camera is extremely difficult to contact by phone. If you do get through to Precision Camera, they are helpful and pleasant though. Sony will write up your problem for the Precision Camera work order. DO NOT RELY ON THE SONY WRITE UP ALONE! E-mail Precision Camera with image and video samples if you have them and describe the problem in detail. Be sure to tell them that the problem is 'intermittent,' or you may get your broken camera back with nothing more than a cleaning.
I am fortunate that this problem didn't happen a couple of months later or my camera would have been out of warranty, and given my experience with Sony repair and customer service representatives, my impression is that they would try to avoid responsibility even though other units manufactured at the same time seem to have had the same manufacturing defect.
If you're reading this, maybe you are having the same problem. Good luck!
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