Reviewer timeout

Hi, some reviewers accept to review a manuscript and leave the tab open after downloading the pdf while working on their review. Then they fill in the form and submit but get an error as the system has logged them out. Some have not noticed the error and closed the tab. The review is then lost but the reviewer thinks they have completed the request or they complain that the system does not work. I guess this could be avoided by a notice “you will be automatically logged out after x hours” or by stopping the timeout? It would also be good to have a save button as some reviewers do not complete the review in one go. Thanks.