I purchased a plugin from techextension about last years ago and recently I have to change my domain name to another one, I contacted the developer and request for a new license for the new domain and I was told that the license purchase for the previous domain cannot be changed and I have to purchase another license for it. I asked the developer if there is anything like this has been stated in the terms and conditions and he provided one with the very fresh newly added terms the moment when I asked - “You cannot allow to Ask Activation key if you have changed Server/Domain/instance/User to use Any Of TE Addon. You have to Buy New License in any case.”
I search a copy of the cache copy and send the screenshot to the developer and he admitted that the terms have just changed.
My advice is to purchase any plugin from the reputable provider especially from Suitecrm store especially the expensive plugin, at least you have good support when comes to issue like this.
Business is just so difficult nowadays.