Have you run the upgrade XML, or does this happen immediately after uploading the files? If you haven't run the XML you should disable the add-on and then run it. Otherwise it looks like you might be using an OpCache and the installer code was still cached when you ran the upgrade. Just run these two queries and you'll be good to go:
ALTER TABLE `uix_node_layout` ADD `separator_type` VARCHAR(50) NOT NULL DEFAULT 'grid' AFTER `node_id`;
ALTER TABLE `uix_node_layout` ADD `separator_max_width` INT(10) NOT NULL DEFAULT 0 AFTER `separator_type`;
Not sure if we addressed the original bug you were having. But to test it I believe this is in UI.X Sidebar style property group. View attachment 138228