I just lost a game. I spent all my time on pressing space every half of a second to center the screen view on my hero. No chance.
The option “Enable Mouse Scroll” is on, yet the screen can be scrolled only by keyboard. I can ofc pick the option “Enable Camera Follow” which makes the screen scrolling by itself but it’s slow and annoying. Needless to say, i don’t want to play like that.
Mouse scrolling doesn’t work on every of four edges of the screen, not just the bottom one as one of the known bugs suggests.
I’m playing on Catalina 10.15.4
Yep, this is especially pronounced in windowed mode, not playing full screen. You can only scroll the camera keeping the curser within the game window at the very edge couple dozen pixels of HOTS. The game no longer considers your cursor moving outside of the active HOTS window over the desktop or other inactive/unselected applications as a request to pan the camera in that direction like it used to for years. It is intensely frustrating.
In my case it’s full screen mode. The mouse pointer reaches all the edges but the screen doesn’t scroll.
I’m curious if yours does the same thing in windowed, and if the same problem is causing both things. The game is way more difficult to play with the character stuck in the direct middle of the screen on camera follow, and the camera unmovable apart from mini-map clicking/spacebar centering.
Having the exact same problem! 
This is listed on our known issues list. Please try CMD+TAB and tabbing back in or Windows mode will work around the issue.
For those experiencing the issue on Windowed mode as well, does the same thing happen in fullscreen mode and tabbing out of the window, then back in? Are you on MacOS Catalina 10.15.4?
I have a similar issue. Occasionally when I join a game I will be unable to scroll the camera, pointing to the spells doesn’t show a tooltip, and with abilities that show a direction, it doesn’t change direction when I move the mouse.
I have found that I can resolve this issue by switching into windowed mode and then immediately back to full screen. Hope that helps.
I am also having this issue along the bottom edge of the screen on Windows 11. I have tried Alt/Win+Tab’ing out and back in as well as switching from “Windowed (Fullscreen)” to “Fullscreen”. I have rebooted both the game and my PC as well as verifying the game files.