Cannot change bridge (with Tor 0.3.0.4-rc)

Trying to replace a bridge in torrc (that had been successfully used for a long time) with another one results in many warnings "[warn] Failed to find node for hop 0 of our path. Discarding this circuit.", and failure to connect.

Only way out found is to edit "state" file and remove the "Guard" line for the previous bridge (with "listed=0"), or come back to previous bridge option in torrc.

I found this while testing further after reporting what I initially thought was a bug in TorBrowser (https://trac.torproject.org/projects/tor/ticket/21768)

Trac:
Username: torvlnt33r