If you notice, when your tabs first come up, they are using different URLs that end up redirecting to the bing results. The video is a little fuzzy for me to make out the exact words in the url, but it looks like “msearches[dot]com” and “mynewtabs[dot]com” or similar that end up redirecting to bing. This is a very common malicious hijacking, and I had the same problem a while ago. They hijack your search results and redirect to bing, and collect the bing referral rewards/comissions.
I had the exact same issue and found out I had a rogue chrome extension installed with malicious code. Disable all of your browser extensions and see if it still happens. I had been using this same extension for more than 5 years, and never had this problem but they had recently updated the extension with malicious code in the update. (Not sure if it was intentional or not.) I narrowed it down by disabling extensions one by one and searching again and again until I found the one that was causing it. (Mine was “MeasureIt” which I used to measure the size of webpage elements sometimes. The extension is no longer on the store, but this code could be in any extension.)
If you google this problem you’ll find tons of reports of a VIRUS doing it. This wasn’t the case for me and malwarebytes did not find any viruses on my computer at the time, (before I figured out that it was a browser extension) but that seems to be a very common method of doing this too, so I would check both, for viruses and rogue extensions.