This has probably already been mentioned but,
I tried the low gravity 2022 summer campaign https://trackmania.io/#/campaigns/41346/28302: (https://trackmania.io/#/campaigns/41346/28302)
and I noticed that when I first started it, there was no initial jump, which I got on subsequent attempts,
I then found a small half button at the bottom right which would cause it, as I'm now assuming, to immediately apply the manialink url, if I click it, reset the run, it takes a second to launch.
Anyway I found that it's possible to block these manialink physics from running by blocking the ip from my pc, so the bug I guess is, that these runs count as valid, without checking if all the external urls and whatever have run successfully.
This is probably already known though, apologies if it is.