You can try to run as administrator once, in order to allow MATLAB to write to the proper license file. If that doesn't help solve your problem you should contact Mathworks support team for help with installation.
You can also refer to the comments on this article: https://www.mathworks.com/matlabcentral/answers/388140-matlab-keep-asking-for-activation?s_tid=answers_rc1-1_p1_MLT