Are you sure?
I can stick around at some servers for a half hour with no visible progress, but upon rejoining, the resources (might) download with the secondary bar present, and fairly quickly. In addition, small resources (ones that take less than a second to download) still use this bar when I rejoin.
Also, servers stall even if I tell Blockland to only download the essentials; it doesn't make too much of a difference. I have realized that changing some network settings will trigger Blockland to use the light-blue loading bar, but it doesn't always work, and when it does, the way I toggled it isn't consistent.