New items in list can't be moved.

Hello. I'm trying to adding some items in one of my list and then moved them to other position. My list is more or less 850 items long. I'm been able to set the right position when I arranged the list, but once saved, all remains as the original list, without updating. Is there any other way to do it ? Thanks a lot.

I´m adding some more info. It's totally impossible to do it in any list. It's very frustrating to get an error 500 ( timeout in the server ) when you try to save a list...and then you realize any change has been done. Please, could you fix it ? Thx.

I tried it just now and could not find an issue with it, which browser are you using? It is possible that the server was just overloaded last time you tried.

Hello. I was using last version of Firefox. It seems the situation has improved, but take into account I found this issue twice a day...with 16 hours of difference between the issues. Does it means the server has been overloaded during all the day ?

Now I'm trying with Chrome and the issue still persists with my biggest list. Once I add a new item, I put in the last position and once saved, it's in the original position, any change has been done. I've tried 3 minutes ago.

I think it's related to the large number of items in the list, it may be worth spiting the list up into sections

Can be selected few items to move them into a new section or must be moved one by one ?

No, unfortunately they would have to moved one by one