Livestream issues with iOS14.4

[Dewcal]

Hi, wondering if anyone can help me?

I am live streaming one camera from BI5 (v5.3.9.11x64) and it is working fine on Android and PC across the web. Viewers on iPads with iOS 14.4 get a quick flash of the image and then an error code hls:3

The upload is "http://IP address:port/livestream.htm?cam=shortname".

Settings in BI are at defaults - is this something I have missed or is there another way to allow iPad viewers to see the feed?

Thanks for any help.
Dave