[0.16.46] Loading bar fills twice in multiplayer with script

[Jap2.0]

I've been noticing this for a while, but I took the time today to track down the exact cause.
In multiplayer, if a server has a script, the loading bar will fill, sit for a second at the end (normal loading), and then, unless the map includes no scripts or you have joined it previously (the latter which doesn't make much sense), the progress bar will fill up again more quickly.

Video attached.

This is reproducible on any public server with scripts running (several include Factorio MMO, although their server doesn't apprear to be on 16.x, Redmew, and Explosive Gaming, as well as many others).

Relevant specs should be in the log, attached (though I can never seem to keep my logs straight; I'm fairly certain this is the correct one, though).

[Jap2.0]

Confirmed for 16.47 (although to be honest I don't think anything changed related to this) on the FMMO server for the Reddit community map.

[kovarex]

It is some internal thing, but since it works I wouldn't consider it a bug.