Initial Value Issue in New Desktop Design

[James_Burns]

I have two tables, one called Accounts_Paid and another called Accounts_Payable. 
A field in Accounts_Paid is Accounts_Payable_IDs which is an EnumList type with base type of Ref to the Accounts_Payable table.

On the Accounts_Payable table the Vendor field has an initial value formula:
ANY(SELECT(Accounts_Paid[Vendor],
CONTAINS(SELECT(Accounts_Paid[Accounts_Payable_IDs],ISNOTBLANK([Accounts_Payable_IDs])),[_THISROW].[Accounts_Payable_ID])
))

In the form to create a new record in the Accounts_Paid table I can add new accounts payables to that record inline. The Accounts_Payable form that opens inline has the Vendor pre-populating to match the Accounts_Paid record as expected. However this does not happen in the new desktop design. For some reason in that format the Vendor pre-populates to the first one it finds alphabetically on the Accounts_Paid table.

Has anyone experienced this issue? Is this just a result of something I failed to do or is this a bug/limitation I need to raise with admins? Any help would be greatly appreciated! 

[AleksiAlkio]

If you think about your ANY(SELECT(..)), is it possible that it generates more than just one value when adding a new record? If yes, then it makes sense as ANY() brings the first value from the list, but it's not always the same.

[James_Burns]

I don't believe this is the issue because it works just fine in mobile and old desktop versions, just not the new desktop.

Here's the formula I'm using for initial value in the Vendor field on the Accounts_Payable table:The initial value formula for Vendor in the Accounts_Payable table.

Here's how the workflow looks on mobile:

 The workflow working in old desktop view.

Here's how it looks on old desktop:The workflow working in mobile view.

And this is not working on the new desktop (nothing else is different):

The workflow not working in desktop view.

[AleksiAlkio · Accepted solution]

You can test this if you add INDEX() & SORT() to your initial value like INDEX(SORT(SELECT(...),FALSE),1). If it still doesn't work properly, I would propose to file a support ticket. 

[James_Burns]

I don't know why it only presented itself on the new desktop version but I took your advise and troubleshooted this way. 
That led me to the formula below which fixed it!

[AleksiAlkio]

Excellent!