After you switch to Guesty, the cancellation policy and rental terms fields on your booking form are blank. This happens because cancellation policy and rental terms are not automatically pulled from Guesty.
You have a few options depending on your needs.
Same terms for all properties. Your terms can be added as default text directly in the booking form field. The form then shows that text for every booking.
Different terms per property. A custom field can be set up in Guesty for each listing, and the booking form automatically pulls from that field for each property.
Both. You can combine the two: set account-wide terms as the default, and allow per-property custom fields to override them for specific listings when needed.