Big problem :( with adobe and original ps6 v13 key bought on very small company

Hello everyone, I bought the original full version of Photoshop CS6 v13 for over PLN 2,000 a few years ago, bought on an invoice for my small company, currently Photoshop is activated on 1 laptop with Core I5 ​​4th gen. with Win8.1 and I have a used new laptop with I5 8th gen. win10 I want to install CS6 on a new laptop so I can continue working, but unfortunately, neither the installation by entering my product key directly, where it also appears as active and registered in my Adobe account, nor the offline installation option works :( After generating the request code, after installing CS6, when I go to the page where I enter the request code, then my product key, and the response code should be generated, the entire Adobe system says my key has been invalidated :((( It looks terrible and I feel totally cheated because I spent a lot of money :( And they're telling me the key has been invalidated, even though it works on my old PS6 laptop, and I hope no one from Adobe disables it because that would be a serious illegal action. I have the option to deactivate it on my old laptop, but I'm afraid that if I do, I won't be able to use it at all. I know and have heard that you can have two Photoshop programs installed on two computers, but you couldn't use them simultaneously. I've never done that either because I only have it on this one laptop. Can anyone or the entire Adobe team help? P.S. I can't afford to pay subscriptions for new versions; CS6 13v is perfectly sufficient for quickly retouching, cropping, and enhancing photos, and then compiling everything in Coreldraw 15, which is where I primarily work.