webrtcbin: Not in the correct state for setting local rollback description

Hi everyone, I couldn't find a related issue or any information on the topic so far.

I have the situation that I am in the have-local-offer state after creating an offer. After that, I get an offer from the remote peer. Normally you would now rollback and set the remote offer (perfect negotiation). However, trying to do so will raise:

webrtcbin gstwebrtcbin.c:4320:_set_description_task:<webrtcbin0> Not in the correct state (have-local-offer) for setting local rollback description

and subsequently:

webrtcbin gstwebrtcbin.c:4320:_set_description_task:<webrtcbin0> Not in the correct state (have-local-offer) for setting remote offer description

I narrowed the error down to _check_valid_state_for_sdp_change. As it seems the check is not considering any rollback. Is this an error, or have I overlooked something?

I experienced the error on 1.18.1 on a windows machine, but looking at the source, I don't expect to be relevant here.