There was a dark mass in the sky that never moved and disappeared suddenly.

I looked out the window of my 5th floor apartment on June 27, 2023 at 7:05am European Time and there was a dark cylindrical mass in the sky (dark grey, black). It was about 2km away from me. It looked a bit like a big bell. It was not moving. I sensed that it was just hovering in one spot. The day was cloudy but bright. I watched the dark object with my two children and my husband for 12 minutes or so. It never moved the entire time. I had to get my kids' bags ready for school, so I left the window. When I checked on it five minutes later, it was gone. Disappeared.
There is a commercial hot air balloon that flies in different parts of Switzerland owned by Vitogaz that is a similar shape and is grey and red. What I don't understand is if it was a hot air balloon: How did it completely disappear from such a height so quickly, and why did I get such a weird vibe from it. Balloons don't move quickly. It would have had to have plummeted to the ground. I have video from 7:09 and then at 7:26 when it completely disappeared. I’m used to seeing hot air balloons in our area. This did not act like a hot air balloon, and it wasn’t in the location that the hot air balloons usually fly. It was closer to me. Usually they stay farther away on the horizon, and I can always see all the colors on the balloons from where I live. This object had no colors.
After seeing this in the sky I was convinced it was not normal. I googled to see if anyone else saw anything and found this report in Lausanne in July 2020. https://www.express.co.uk/news/weird/1315827/UFO-sighting-video-Lausanne-bell-UFO-real-aliens-news?int_source=amp_continue_reading∫_medium=amp∫_campaign=continue_reading_button#amp-readmore-target
The report here is very much the same as my experience, except I didn't have trees for the object to possibly hide behind. There are also many reports that these sighting are just the Vitogaz balloon. I really don't believe this. And why have other people in Switzerland been alarmed by similar sightings as well. It just seems like something isn't right with all of this. I'm not satisfied with it being a commerical balloon for all the reasons I listed above. I have shown the footage to a few local friends who agreed that it just doesn't seem right. I hope all of this information is helpful, and I hope this event isn't dismissed as another balloon sighting. I believe it really needs to be looked into further.