How to "freeze" custom UI ribbon tab when working with two workbooks ?

I have a custom ribbon tab made via Excel "Customize the Ribbon..."
which I put the tab as the first tab (before HomeTab),
and the name of tab, say "MyTab-1".

I have another custom ribbon tab made via Custom UI program
which I put the tab as the last tab,
and the name of this tab, say "MyTab-2".

When I work with two workbooks opened which I activate back and forth on each,
the ribbon tab is always coming back to "MyTab-1" IF the last active workbook is in "MyTab-2".

Example :
Workbook-1 and Workbook-2 are opened. (WB1 and WB2).

I am working in WB1 with "MyTab-2" active.
Next I need to see WB2, so I activate WB2.
But then in WB2, the ribbon "MyTab-2" jumps to "MyTab-1".
Since I still need (and always need) to work with "MyTab-2",
that "jump" caused me to click "MyTab-2".

The next time, when I activate WB1,
again, the ribbon "MyTab-2" jumps to "MyTab-1" in WB1
which caused me to click (again) "MyTab-2".

That kind of situation is a bit annoying for me,
because every time I change/activate the workbook back and forth -
I always have to click "MyTab-2" again and again.

It's not happening if the active ribbon tab is the default (built in) Excel ribbon tab.
For example, I work in WB1 with "FormulasTab" active.
After I go to WB2, the "FormulasTab" stay put. So "FormulasTab" shows in WB2.
Go back to WB1, the "FormulasTab" also stay put. WB1 has this "FormulasTab" active.

I wonder, is there a way to freeze "My-Tab2",
so whenever I go back and forth within those two workbooks, "My-Tab2" always active ?

Any kind of help would be greatly appreciated.
Thank you in advanced.

Hi Keebelah,
Thank you for your answer.
I will try your suggestion.