Toolbar configuration lost

I have set up a bunch of external tools (Settings | Tools | External Tools). For quick access, I added some of them to the main toolbar (Settings | Appearance & Behavior | Menus and Toolbars | Main Toolbar -> Add Action). Problem is - the icons disapear after PyCharm's restart. I noticed it when upgraded to v. 2019.3. The problem first seems to be reported 11 years ago: https://intellij-support.jetbrains.com/hc/en-us/community/posts/206973955-external-tools-loses-my-configuration and reported numerous times since then, but I haven't found a solution. Anyone having the same problem? Any workarounds? )