Are tabs added via Builder still working?

Curious if tabs created with Builder's Custom Attributes are still working? I noticed some of my metaboxes that previously had fields split up into tabs stopped rendering the tabs about a year ago. But I never investigated until now.

Finally investigating, I looked at the code Builder generates, and it doesn't seem to be including the tabs array key where tab IDs are declared. I have two tabs declared in Builder's custom attributes for the field group. I tested on a basic WP install with no other plugins activated other than MB, MB Tabs, and Classic Editor, with the Twenty Twenty theme activated.

Here are the custom attributes I specified:
https://www.dropbox.com/s/jwb5s64p7doghol/metabox_tabs_builder_custom_attributes.png?dl=0

Screenshot of the rendered MetaBox:
https://www.dropbox.com/s/3b4ssx8tqm32bj6/metabox_tabs_missing.png?dl=0

And the resulting code Builder generates:
https://pastebin.com/J60a7f70

Note the missing tabs key in the code.