Put the following css in a file, I called mine noblink.css

.cm-cursorLayer {animation: none !important;}

Put the file in your Obsidian snippet directory. On a Mac it is here: ~/Library/Mobile Documents/iCloud~md~obsidian/Documents/Obsidian/.obsidian/snippets In the app (on the Mac) go to “Preferences > Appearance”, scroll to “CSS snippets” at the bottom to activate the snippet.

screenshot of obsidian css settings

I found this tip here: https://forum.obsidian.md/t/allow-stopping-the-cursor-from-blinking/39819/6