Mystery display glitch

Hello. I’ve run out of ideas on how to fix this problem. I’ve tried looking for solutions online and in forums, but can’t find a similar issue. Problem is this:

Occasionally the display of my website appears glitched, or all messed up. It happens across all devices and with multiple users in different locations. It will stay like this for a period of 5 to 10mins, sometimes longer. Then all by itself if goes away.

Screenshots during problem:

[url=https://postimg.org/image/8da6lw1hn/][img]https://s17.postimg.org/nm03znv67/Screen_Shot_2016_09_08_at_11_20_58.png[/img][/url]

[url=https://postimg.org/image/gwtkjn9u3/][img]https://s17.postimg.org/s9661fij3/Screen_Shot_2016_09_08_at_11_20_54.png[/img][/url]

[url=https://postimg.org/image/rkxbihjt7/][img]https://s17.postimg.org/dr8ytfr7z/Screen_Shot_2016_09_08_at_11_20_42.png[/img][/url]

Screenshots when normal:

[url=https://postimg.org/image/ujqvw7orf/][img]https://s9.postimg.org/me8ty20in/Screen_Shot_2016_09_08_at_11_34_29.png[/img][/url]

[url=https://postimg.org/image/rqxoc6oez/][img]https://s9.postimg.org/a0vzr5au7/Screen_Shot_2016_09_08_at_11_34_24.png[/img][/url]

1. I’ve upgraded the server running this website (AWS EC2) thinking that it may have been a resource issue, but that didn’t fix it

2. I’ve updated to latest WP version, still the same as before

3. I’ve uploaded the database again, but that didn’t solve the problem

Any suggestions would be very much appreciated! Thanks!