Sorry about this. Updating Objo Studio should preserve your activation, so you shouldn’t need to keep entering your licence key.
It looks as though the repeated activations may have filled the available slots, even though you’re using the same Windows installation. I’ll check the activation records against your order and help get you unblocked.
Could you open Settings > Licence, click Export Diagnostics, and send me the resulting text file privately? The report excludes your licence key and personal details. It should help me understand why Studio is no longer recognising the saved activation.
If you remember which version you updated from, that would also be useful.