Some donor records show a "Donor household not found" message where the household panel should appear, even though the donor clearly has a household.
This is a known display bug, not a sign that the household or its history was lost. The donor's household still exists and its data is safe. CoolFocus is not able to load and show it on the donor record right now.
Refreshing the page does not clear this message. If you see it, there is no workaround on your end yet.
Engineering is aware of this bug and is working on a fix.
Contact support and let them know you saw "Donor household not found" on a donor record. Include:
The donor's name or record link.
When you first noticed the message.
Support can confirm the household data behind the scenes while a fix is in progress.