and no, that is not because their servers are crappy connected, they are not but because of unstable connection the users have - most often their damn mobile/wireless/3g/4g/5g uplink that offers great bandwith (theoretically) but forget to mention the downside which is are very poor stability of connection, especially in dense urban region where far too many people connect to the internet via the same antenna. but the bulk option is what DE suggested themself to test out. connection or bandwidth as well as routing problems between the two points of the connection or even other software using the own bandwidth without being allowed to (not only malware does this but legit ware too at times). and if not, it can gae many other (usually temporary) reasons like server being at max. Yes, the 'bulk' option is very often the problem solver. At least that fixes the error for me every time it presents, just altern between checking and unchecking those options until its back to your regular download speed.

If the error presents again try checking those options again. Necroposting but I think I found the solution for people that only uses windows anti-virus, uncheck Bulk download and Agressive download options in the launcher.

Why is my steam download speed so slow