I have been in this situation- THS advise you to work it out with the owner .
The sit guarantee covers trips that are curtailed when HO comes back early . However the first $100 of a claim is deducted Sit Cancellation Terms - sitter | TrustedHousesitters.com
I disagree with those who are suggesting that if an owner says you can stay on with them that’s fine and a solution to them breaking the agreement. Yes it means you don’t have to find alternative accommodation . However you have to live with the owner . Some sitters work from home during the sit , or are an introvert and find social interaction with others exhausting . Some HOs expect you to carry on with the pet care ( dog walking etc ) when they return early. There are so many scenarios where being expected to just stay on with the homeowner when they return early is not comfortable for a sitter. Imagine if a sitters said ( without being invited) I’ll just stay an extra few days with you . Most homeowners would be uncomfortable and feel this is intrusive . Yet some assume the sitter will be fine if they come back early.
If a sitter said to a host I’ll be arriving a day late / leaving a day early they can be suspended from the platform . If a host does it there’s no implications for them .
Having experience this twice early on in our house sitting experienced this is my advice . Don’t expect help from THS . They can’t prevent the HO from returning to their own home . What you can do is have a backup plan for each and every sit and write an honest review to warn future sitters .
https://forum.trustedhousesitters.com/t/home-owner-curtails-sit-by-coming-back-several-days-early