These are merely assumptions, based on Jolla’s response to this issue in their original post.
In the second post, they allude to a possible solution found in collaboration with the manufacturer, which appears to be conclusive.
Although, as you say, this remains a likely possibility given its proximity, it isn’t necessarily the cause. It may also be related to what @Koza shared here
Let’s wait for Jolla to make an official announcement regarding this issue