I'm on Blender 5.0.0 with Zen UV 5.2.1 and Core (2,0,0) on macOS 26.2. I've used this functionality a lot in the past, but either I'm doing something wrong or there's a bug hidden somewhere: When I select an edge and hit "Match and Stitch", nothing happens. I get the message "Only one Island has been selected. For normal operation, two islands must be selected." You can see my settings in the screenshot attached. Zen Sync is on. Steps to reproduce: 1. open an empty file 2. create a cube 3. in UV Editing, set "Zen Sync" to on 4. rip move one of the polygons of the cube 5. select one of the edges on either side of the ripped polygon in the UV viewport 6. hit "Match and Stitch" in Zen UV - Transform, with the settings shown in the screenshot Expected outcome: - the polygon that was ripped will move to the selected edge, and will be stitched to the other polygon. the shape basically looks like before. Tested and works for me in Blender 4.5.3 with ZenUV 5.0.3 (except for the "rip move", for that to work had to activate Zen Sync after rip move) Actual outcome: - nothing happens, message "Only one Island has been selected. For normal operation, two islands must be selected." https://cdn.discordapp.com/attachments/1465265647813529620/1465265647994015764/Screenshot_2026-01-26_at_09.34.01.png?ex=69787a79&is=697728f9&hm=1f0179a814cbed4c140839d5b6c8315f16aede93c295acf5027338ddccb820a9&

Hey. Thank you for the detailed description of the problem. The Match and Stitch operator performs two operations: 1. It aligns one island to another based on the selected mesh elements. 2. It stitches the selected elements if possible. By using feature #1, you can match islands that do not share common vertices. Blender has always worked in such a way that when UV Sync Select was set to On, selecting one edge would also select the corresponding edge in the mesh. However, starting with Blender 5.0, this is no longer the case. The developers changed the behavior to be more consistent with other modeling packages, and now in UV Sync Select – On mode you can select only a single edge. In practice, it now behaves the same way as it previously did in UV Sync Select – Off mode. So, in the example you provided, when you select a single edge, you end up with only one selected edge. From the perspective of Zen UV’s algorithms, this means that only one island is selected. The operator points this out accordingly. For normal operation, two islands must be selected: one base island (which will not be moved), and another island that will be moved. This may seem a bit complicated for a simple match and stitch task, but the way Blender worked previously did not allow this to be implemented more simply. Now this operator is subject to refactoring and will most likely be split into two separate operators. At the moment, I cannot say exactly when this will happen. To perform match and stitch in your case, you need to select one more island — in other words, also specify the island that the operator should interact with. Returning to the state where you have selected one edge of an island: simply click the button with the arrow located immediately to the right of the Match and Stitch operator button. This will create the selection you need. https://cdn.discordapp.com/attachments/1465265647813529620/1465270252412604539/image.png?ex=69787ec3&is=69772d43&hm=82053e7226599417b9f2017f71beccb137f4bc798c90f7b0e084f54947cbb07b&

Thanks for the detailed explanation. Looking forward to whenever this will be refactored and until then will set up myself some makro which first always runs the arrow, then the operation. I think that should work until the "clean" fix.

The developers of Blender have left you the option to work as before. To do this, switch the option Sticky Selection Mode - Method for extending UV vertex selection to Shared Vertex mode. https://cdn.discordapp.com/attachments/1465265647813529620/1465687370803314759/image.png?ex=697a033c&is=6978b1bc&hm=0e9b30964ecaf01831aa279701c330db7e9900e07ef8ef820f0e99729b226b9a&