Auto-Refresh Now() calculation bug - Zoho CRM

Just dropping this here as a heads up (as I doubt we are the only ones affected) - I have raised with Zoho CRM support but if anyone is relying on the “Automatically refresh formula fields containing the Now() function in real-time.” feature in CRM for anything important then you might want to check it is working correctly.

We have used it for quite a long time to calculate contacts age from a date of birth field with the formula

Floor(Datecomp(Now(),${Contacts.Date of Birth})/1440/365.25)

because we have some workflows that merge the result into task descriptions I can see from past occurrences it has been working fine - but today I noticed that for any contacts born before todays date in 1970 - their age will be returned as 56

Anyone born after todays date in 1970 and it is returned correctly.

Turning off “Automatically refresh formula fields containing the Now() function in real-time.” and the fields return to what they were last calculated as on edit and update correctly when the record is edited.