Issue was caused by starting Icon Preview render job from two places: - Texture buttons for small icon preview - Properties panel in image editor for large icon of texture This preview job is starting in suspended mode and if new instance of the same job is starting, suspended job will be totally stopped. This is normally for cases when you're changing different settings -- in this case you'd wouldn't want re-render be triggered on every slide change. But what we've have with brush preview is that two instances of this job were creating for large and small icon separately, but because of described policy only one icon was rendered. If suspended job is getting to be stopped, check if it was started for the same icon resolution and if not, that resolution will be also rendered in new job. So it'll be still minimal re-rendering happens, but in cases when job was started from two places for different icon sizes it'll work just fine.