How does having Chrome devtools open change behaviour?

I had a similar question in stack quite some time ago. Mine affected the way and speed JS was executed, specifically JSPerf was being slower when I had the console open, and the tests were completely messed up you can take a look at my answer here

Still, might be that some of the issues might be related to your config of the devtools, as this user pointed out in this question https://askubuntu.com/a/633838/742250

Have you tried in an incognito window or in other browsers? Mozilla or Safari?