Odd behavior - Chromium alt-tab icon merges with other apps

Hi there,

I am running Chromium on Gnome. When I sometimes run alt-tab, I do not see a Chromium icon, and then I realize the Chromium windows are grouped with another app (if I hover over that app icon). I have observed this happening with 1Password and Slack.

Has anyone run into this? Have a fix?

Thank you.