Danbooru multiple download

Hi everyone,
So, I'm checking images with iqdb and then download them, but here is the problem: I noticed that downloading images AND loading pages are not simultaneous, but one by one. I remember it wasn't like this like 2 months ago.
[Right to the problem] Is danbooru allowing downloading multiple images at the same time (like multi stream download), or am I getting blocked by danbooru and should download one by one (like FIFO)?

You can download multiple images over the same connection, one after another. You definitely should not create multiple parallel connections. Danbooru is already under high load from multiple people trying to scrape content way too fast, so if you cause a suspiciously high load, you can easily get blocked. Downloading images one by one is definitely recommended.

Yes, but once I start downloading (my list of files I push through iqdb is around 30 per 2 min and then I just check for similarity) it just stops working on one of tabs/downloads, slows the speed to minimum, then stops at all and I wait around 10 min just to receive connection. It's usual like that or I have some issues on account/browser?