You could try
- entity: cover.garage
include_history: true
remove_repeats: true
exclude_states:
- "unknown"
- "unavailable"
Since filtering of excluded states is done before the removing of repeats, this should ignore it if it goes from from “on” to “unknown”/“unavailable” and back to “on” following a reboot.
If you only want the latest state to be shown (e.g. if it is opened and closed several times in the day) you can us the max_histroy option as well, like this:
- entity: cover.garage
include_history: true
remove_repeats: true
max_history: 1
exclude_states:
- "unknown"
- "unavailable"