I have this issue in designer for any time I am trying to write something in the expression binding. This doesn't happen on scripts or anywhere else that I am aware of and I have restarted, redownloaded, and updated my designer. This seems to be just persistent on my computer as it doesn't seem to be an issue on other devices.
Whenever I press tab to indent, the text cursor doesn't recognize it and adjust appropriately. In the image below, the cursor is right after the double quote on the text "test" and that is the end of the line -- I cannot get the cursor to move past that. However if I do type, it will recognize that the end of the line is at the , after 1.