When adding a cover to HomeKit, only required characteristics are implemented (current_position, target_position and position_state) but hold_position, which is an optional characteristic, is not implemented, although Home Assistant provides Stop Cover functionality. Without it, covers cannot be stopped using Homekit automations.
Another case scenario: you can now use a Hue Remote in HomeKit to open/close a cover, with one button toggling open/stop and another for close/stop like in a regular cover remote. It works fine with Automation Shortcuts when using Homebridge because Homebridge does implement hold_position, but covers added to HomeKit from Home Assistant do not show that option.
Here’s some info on Apple’s dev pages.