TorBrowser connected through Chutney uses real external Tor nodes

I have setup a Chutney tool successfully and was wondering if I can route my traffic through a Chutney-made network and to the internet. I was going to test that using TorBrowser and providing custom bridge in the browser tor settings.

For the network setup I used:

./chutney configure networks/bridges-min
./chutney start networks/bridges-min

./chutney status networks/bridges-min gives me information about a network made of 7 tor instances:

test000a     is running with PID 20520: Tor 0.4.3.5.
test001a     is running with PID 20523: Tor 0.4.3.5.
test002a     is running with PID 20526: Tor 0.4.3.5.
test003ba    is running with PID 20529: Tor 0.4.3.5.
test004r     is running with PID 20535: Tor 0.4.3.5.
test005br    is running with PID 20538: Tor 0.4.3.5.
test006bc    is running with PID 20541: Tor 0.4.3.5.

Now, I assumed test005br is a bridge. I figured out it’s port and provided to the TorBrowser a following bridge info:

127.0.0.1:5005

Using TorBrowser I opened a random website and checked the Tor Circuit info and it tells me that indeed my first hop is a "Bridge" (I assume, it’s my Chutney bridge). But next hops are real Tor Nodes out in the wild, not the test nodes in my network! I surely didn’t expect that.

So, why is my Chutney network connecting to the main Tor network (or it seems so to me)? Can I prevent that and use only my local network to access the internet through it?