Plasma 5.26 has changed the toggling through virtual desktops. Before, and since the days of Plasma 4, you could toggle via mouse wheel or your preferred key combo though your desktops and at the end, it jumped back to desktop 1. Now, it will halt on the last. You cannot reach the first one, or the last one when you are at the first. For me, it’s uncomfortable. This new behavior seems to be fixed on the idea of a row of desktops but that’s not my mental model. After 15 years using Compiz and later Kwin on Plasma 4, my mental model is the Cube the Kwin devs removed a year ago but PROMISED to bring back (I have even offered to support the recreation with a bounty in this tracker, without responses). Now, with this fixed paradigm of a row of virtual desktops with a start and ending, the Cube paradigm is getting destroyed.
I often have an Amarok window open at the desktop left to my browser, which is desktop 4. Now, I cannot reach it with a single key press or mouse wheel turn. When I have more important work to do on other desktops at the right, the space becomes limited. Before, I could directly switch to desktop 4, now this doesn’t work anymore. Working with media creation like video editing windows, file management and galleries, Gimp, terminal windows, virtual machines and remote desktops is in the same way inconvenient and limiting now with this approach. Dragging a window on desktop 1 to the left to maneuver it to desktop 4 is also impossible now.
I somehow get that you try to mimic the macOS paradigm with the new Overview effect for light notebook usage but this shouldn’t consume established workflow paradigms for power users. At the least, this should be an option.

KDE Plasma: 5.26