Garbled Google Sheet

Hi, I’m having an issue where my Foundation Template Google Sheet begins looking garbled with weird overstrikes and funky colored graphics. Has anyone else experienced this? How do I solve this? I’ve attached a screenshot to show what it looks like. Thanks in advance for any help.

I had that going on once, seems just clicking into a different sheet and then back again cleared it up.

Hi jpfieber! Your recommendation seemed to work (at least for now). I’ve been using Tiller for years and never had an issue like that before. Thanks for your response.