Safari hangs when saving a pdf

this is a long running issue (across multiple versions of OS and Safari) and I don't have time to troubleshoot it but it is very annoying. I end up force quitting safari each time. The behaviour is as follows:

I get a link to a pdf say in an email (or on a web page). I open this in safari and then 'save as' to store it on my machine. (It prints fine with no issue) Then safari appears to hang (no response, fans eventually start speeding up). I have to select another app and then force quit safari. I do find that it did actually save the pdf file to my disk. So it seems to hang after performing this part of the operation.