私の日本語の知識が限られているため、この質問には英語でお答えします
It is likely that you can access your account on the device you originally logged in with because the session has not timed out on that original device. You will be prompted to re-enter your password and log in again in the future. Therefore, it is recommended to follow the guidelines shared in the following MATLAB answer thread to successfully recover your account: https://www.mathworks.com/matlabcentral/answers/429927-what-do-i-do-if-i-exceeded-the-limit-for-failed-login-attempts
Hope this helps!