Describe the bug
Why does the Block Inserter between each block no longer show all blocks? Why is it showing these 6 blocks? They're not the Most Used blocks. I have never used the RSS block even once so why is it showing?

Why am I forced to open the Block Inserter panel when I click the Browse all option?

Not only am I forced to open the Block Inserter panel, by doing so, you close the Settings Sidebar on me, forcing me to have to reopen that again as well, after I insert the new block.

Vid: https://share.getcloudapp.com/jkuZ4bYR

You're making it harder and harder, and more time consuming, to edit content with each release! Not to mention, how many extra clicks I now need to make to open and reopen panels because you close them on me, or because you don't show me all the blocks I want to see.

To reproduce
Steps to reproduce the behavior:

1. Edit page
2. Hover cursor between blocks to show Add Block icon

Expected behavior
Can no longer scroll through all blocks when trying to use block inserter between blocks

Editor version (please complete the following information):
-WordPress version: [5.5]
-Does the website has Gutenberg plugin installed, or is it using the block editor that comes by default? [default]
-If the Gutenberg plugin is installed, which version is it? [e.g., 7.6]

Desktop (please complete the following information):
-OS: macOS Catalina 10.15.6

• Browser: Firefox 79.0