What is the field type of your custom email address field? Free form text?

Field is set as 'Email Address' type. I have it on the customer form, but then pull it from there to transaction form (invoice) I tried using Store value enabled and disabled and that didn'\t have any imapact. Invoice form also uses Email Address as type

Can you share the setup for that workflow action?

I have two states: Button and send email activity. See screenshots for the button, transition and the send email. For the testing purpose I decided to use a free form address - to exclude the field configuration. I think the issue that I'm seeing is somehow related to the transition, but really not sure. I'm too new to NS and have no experience with it yet.

Can you try leaving Event Type and Context fields blank for the Send Email workflow action?

I tried that now but still ending with the same issue:

You have your event types and contexts narrowed down pretty tight. Is that on purpose? Try clearing the event types and selecting all contexts for you actions and transitions

Yes, I ahve done that now. I woudln't say it is on purpose, but I'm really just learning this, so I only selected what I thought was required.

That makes sense. I’ve always taken the approach of leaving those as “inclusive” as possible unless I know for sure I need to restrict something. I usually just leave them as the default whenever creating a new action You may need to just delete the actions you’ve made and start over using the default settings