There is a change in the default behavior of documentation in MATLAB starting from MATLAB R2021a release. From this general release:
- When running MATLAB with an internet connection, the ‘Help browser’ will display the web documentation by default.
- If an internet connection becomes unavailable, MATLAB will display the installed documentation instead.
- When running MATLAB on a system without an internet connection, the Help browser displays the installed documentation by default.
All programming aids tools and search suggestions will still use installed files to get the information they need.
If internet connection for MATLAB host machine is slow, it may cause documentation pages to take a long time to load. In such a case, one can change the default documentation settings to view installed documentation using ‘Preferences’ option. Installed documentation will already be made available on the host machine while installing MATLAB.
To change the default documentation location,
- On the ‘HOME’ tab in MATLAB, click ‘Preferences’ in the ‘ENVIRONMENT’ section.
- Select MATLAB > Help and change the Documentation Location.
The above steps are also shown in the image below. For more information, see Help Preferences . 
