Disappearing Traces when duplicated on both sides of the board

[Forgotten_Machines]

Hi. When laying traces for a ground connection that should go on both sides of my PCB for heaviest connectivity, it seems that whatever side I lay, the opposite side disappears automatically. Here’s a video showing this in action: https://youtu.be/45jU3eLQXOc

Any ideas why this might be happening? I shut down and rebooted in case it was a glitch, but it is still happening. Perhaps this is a setting or some conflict? Strange that the trace just disappears without prompting me or giving me some other error though.

Thanks for your help, everyone!
Best,
AJ

[retiredfeline]

TL;DS: There’s a setting for the track router that deletes duplicate tracks. Unset it.

[RaptorUK]

There sure is . . .

[Forgotten_Machines]

Oh, amazing, thank you both for telling me (and showing me) this option!