This will be because you live in the UK and I use imgur.com to host them (even with a WordPress subscription I only have limited space).
Alas due to the recent ill thought out digital bill (with over 20 years in the IT industry I could have told them from the start it would not work as intended, would have bad side effects, would not stop access by the people they are trying to stop (those kids will now be using VPNs) and is just shifting responsibility from parents) imgur.com have decided that rather than requesting you prove your age to see their mature content they will just block access from the UK. It is a free service after all.
So what am I going to do? Not sure. Imgur.com is free and provides a service designed to work with forums. There are not many out there and almost certainly the other free ones will probably also block the UK. Certainly I am not going to copy over and re-link something in the region of 3500 photos (yes that many).
I know I have been slow recently but I will still be publishing. I will probably have to use a VPN to upload (I have a subscription to NordVPN (from when they took over AtlasVPN) for when I travel else am in a coffee shop). Hopefully in time the UK will once more get access to imgur.com.
dapprman 
Since I’ve used up all of my allotted space on my WP account and am hesitant to pony up for a paid plan, my blog images have been hosted on flickr. It is true that free flickr plans only hold so many photos, but I have a Pro plan due to my photography. So I just pay flickr vs. flickr and WP.
I do have a Flickr account, but a free one. I did subscribe a long time back but then just did not use the account enough. I also had my fingers burnt by Photobucket when they changed direction. Also before then used WebShots and I think I had a paid account there, but then they changed completely to try and become a photo printing site.
I say give Flickr another look around. Yeah, there have been changes over the past 20 years, but surprisingly there’s a lot of “back end” stuff that looks the same as it did in 2004. One thing in its favor vs. sites like Photobucket is that after years of corporate ownership it is now owned by SmugMug, a smaller photo company. And they bought it so that Flickr wouldn’t go away forever. I know there was grumbling during the purchase, as SmugMug had to ramp up the paid plans after years of basically giving everyone free unlimited storage, but it was needed.
Catch is the cost. I’m presently paying £30 per year for here and that would add another £60. If I was still posting every 1-2 weeks I could be cheeky and see if anyone will donate, but certainly not these lazy days.
(any shops/makers willing to lend me pens for impartial reviews will help fix that ^^ )
Yeah, Pro level is not cheap, but since I don’t pay for WP besides $20 for some extra storage, and I use Flickr for other things it’s worth it to me. I’d rather not pay for anything (obviously) but those days of Everything Free on the Internet are gone (or you pay for it in other ways like lots of ads and data harvesting.) I don’t have a lot of digital subscriptions, nor want them. so I have to be strategic and Flickr just pencils out for me.
I assume with pro level you do not get adverts with your cross posting?
No, you don’t. That’s one of the benefits, but the biggest is the copious photo storage.