I just found out about a bug in the Engines widget. I believe this was always updating automatically if you bought a new engine. However, I just this morning found out this wasn't the case anymore. I had created a Engines widget while having 3 Swallows, I then upgraded the engine house and bought my 4th Swallow. This however didn't pop-up in the widget. I was confused and didn't know what to think of it. This morning I bought my 5th Swallow and this one didn't show in the Engine widget either. I had to manually delete the widget and add it again to have all the engines show up. This worked immediately.
Sorting the engines differently didn't work. Neither did minimising or changing the view of the widget. Only way to solve it is to delete the widget and add it again. This isn't much work and I can't really be bothered that much, but I do believe it is a bug nevertheless.
Version: 81.0.4044.138 (Official Build) (64-bit)
Server: DE05 - Kurbelwelle.