Which version of Movie Edit Pro did you update from?
AFAIK - Shift + T has not been used as a keyboard shortcut for Save as takes for several years, nor does a dialog box open for entering details, nor do they have a .TAK file extension.
Takes are saved straight to the Takes folder and receive the same name(s) as the video clips they are from + a 4 digit number with the filextension .TK2 as can be seen below.
The keyboard shortcut for saving a take is Shift+K, however I am finding this is not working consistently in MEP 2022.
The alternative method is to right click the video object and select the function from the pop-up menu, however you have to make cuts where you are setting I and O points for the video clip when it is on the timeline.
. . . . save a take like in previous versions using the keybord ? used to be I for In O for Out & then Shift+T so the dialog box would open & You could write the description . . . . I Used a 2017 version until recently . . . .
I have checked with earlier versions of MEP, and the shortcut and method you described above is not a feature of in any version of MEP going as far back a MEP MX (2011), the versions which can save takes are as I described above.