Initial text value misunderstood as date

[Dub_App]

Hi,
I set a text column ("Aspect ratio") with "16:9" as initial value (without any kind of validation). 

When record is created this is the result:

As you can see, the content its a dummy date as text (but misunderstanding "16:9" as a time value).

The workaround was add an additional text ("Ratio 16:9") as initial value to avoid the weird convertion:

My humble opinion is that it is a bug.  But if I am wrong, please let me know.

Thanks!