Download Data Issues when selecting Years

After a month I am still unable to download data from ERA5, unless I choose each year separately. I am trying to download T850 from 1961/2020, but whenever I try to select those years,it wont let me. I was able to download from 1961 to 1990 (23Z/00Z/6Z/12Z/18Z) but when I try to download 1991/2020 or 1961/2020 it just wont let me. What can I do?

please have a look here: A new CDS soon to be launched - expect some disruptions