Video's don't play in Chrome due to anti-virus on UTM

Question

Hello 
 
 I'm new here and I have a question about the Sophos UTM. We have problems with playing videos (html5 / mp4) in Google Chrome. In Firefox we don't have this problem. We've tested this on multiple computers and with multiple accounts. All Chrome add-ons are disabled or removed. 
 
 When we disabled antivirus scanning the problem is solved. (see attached screenshot)

We found this problem on: 
 
 http://thevoice.vtm.be/audities/707 
 http://thevoice.vtm.be/files/e29b5a40859adb9372ad435fc7745372.mp4

We can download the video file in Chrome. The downloaded file can be played in Chrome. The direct link can't be played. 
 
 On the following sites we have the same problem:

https://onderwijs.hetarchief.be/collecties/126831 (account needed) 
 http://www.tv5monde.com/cms/chaine-francophone/Revoir-nos-emissions/Et-si-vous-me-disiez-toute-la-verite/Episodes/p-32063-Elcos-au-chevet-des-victimes-en-RDC.htm 
 http://learnenglishteens.britishcouncil.org/uk-now/video-uk/weddings

Chrome seems to choke on something. Is this a Chrome bug or a Sophos bug? Do other users of the UTM9 have the same problem? 
 
 Kind regards 
 Koen De Vreeze 
 IT-Coordinator SFI Melle

JasonBrown · Answer

I've had the same issue as well, and there has been a few threads I've come across that discuss it and so far the best work around I've found is an A/V exception that targets this regex string:

edit: forums is messing with syntax so i made it a picture.