Created attachment 137850 [details] distracting non-disable-able icons that look like mouse pointers As of upgrading to 21.04.0 today, I've found working with kate (which I have been using everyday for a long time) extremely irritating, and really hard to work with. The source of this irritation is a new superfluous UI element. Some new icons I'm not sure about the function of (they don't seem clickable) that do look like mouse pointers --and thus are extremely distracting, as it seems as if the mouse pointer is there, twice-- are now present on top of the line numbers and folds columns. Attached screenshot highlights the issue. I haven't been able to find an easy way (other than reverting to previous package) to disable these. Please remove these or otherwise provide a way to disable showing them.
That seems to be a problem with whatever icon theme you are using. It doesn't have icons for right arrow and left arrow. The buttons are a new feature, which provide an extremely important functionality i.e., History. Clicking left button takes you back in history and clicking the right one takes you forward. Though of course you need to go somewhere first for these buttons to be enabled. Try using quick open or jump to a definition using LSP. The buttons will allow you to jump back.
Switching theme from breeze dark to breeze and then back to breeze dark fixed this. They're look like < > characters now, and behave as described. It must have been some bad handling of upgrade situation with some old version's services still running.