CUBASE 5 licence gone ?

(Haven’t used this forum in years and i guess my account was deleted so i had to re-register)
So,here’s the deal…
Been using Cubase 5 since 2009 i think…upgrade from C4 which was an upgrade from C3
Used C5 mostly on WinXP and in the last 2 years on Win7(32bit)
The time has come to get a new PC…and so i did…Win10 (64bit)
The plan was this:upgrade to Cubase 9.5 to use on the new PC and still use C5 on the old PC (which i have everything running
smoothly on 32bit) by using the dongle on the PC needed in any given time…
I installed C9 on new PC yesterday and authorized it…
Today i wanted to do something with C5 on my old PC so i put the dongle back in that…but…poof…Cubase 5 license is gone…only Cubase 9.5 licence appears…
Hence i cannot use Cubase 5…
Was my plan naive and stupid?
I expected to have the C5 licence intact the same way i have the old C3 there…
Can anyone help please…
I have lots of old projects that i cannot open on either PC
The old one doesn’t recognize its licence anymore…the new one is 64bit and my old projects all use 32but plugins
Is there a way to revert back to the old licence?
Thanx

Update… the license…
database on…your…old…computer…

yes i did that…but i guess something went wrong…
did it now and its fine…thanx!