tofuTAT You seem to have encountered a fairly old issue. Previously, when using a mesh attachment and enabling Trim whitespaceX/Y, the mesh would not display correctly, but this was fixed in Spine 3.7.77-beta in 2018: EsotericSoftware/spine-editor260
If you are using a newer version than that, but have encountered this problem, that is strange. For our reference, could you tell us which version of Spine you are using?