MAX Function in JIRA Product Discovery Fields

[Mike Gargano]

When I try to use the MAX function in JIRA Product Discovery in a custom formula expression I get an error "Could not parse expression" 

The Expression I'm writing is " MAX({Field A},{Field B}) "

I'm assuming this is a limitation of JIRA Product Discovery based on: 

https://support.atlassian.com/jira-product-discovery/docs/expression-based-formulas/

vs 

https://support.atlassian.com/cloud-automation/docs/jira-smart-values-math-expressions/

I'm guessing that JIRA Product Discovery just doesn't support Functions. 

If anyone could help it would be appreciated.