The need to protect citizens' health goes without saying, but democratic life must still continue and elections must be held in due form, as they usually are.
Candidates always visit polling stations in a respectful manner. All candidates have rules to follow. So, I don't see any reason why candidates should be prevented from going there to see if everything is going well, while respecting the rules, not only the ones that existed in the first place, but also the health rules that have been added to them.
I don't think this is a problem that prevents us from visiting the polling stations and checking if democracy is going well.