Alright, so it seems this issue is related to a library we introduced in v2. We will fix the issue in the coming releases. In the meantime this should only affect Editors 2018.x and below opened with Hub 2.0b3.
We changed the way the Hub communicates with the Editor in 2019.1 so I didn’t see any performance hit there. For 2018.3 you can still use Hub 1.6.
We will address this as soon as possible. Thanks for reporting it!