Images loading in slowly on new server

[Rinsler]

Hi, I have just migrated my website to a new Windows Server 2016 and the images, although they're now being loaded in via http/2, are taking an age to come in. It seems like they are requested at the same time, but can't begin to load in until the last image has been rendered:

https://www.webpagetest.org/result/19110...view_step1

Also, some SVGs take over 10 seconds to come back. This is only apparent on this new server.

Thanks in advance

Ben