With the following configuration only additional channels has min-DR=2 set. See region screenshot below.
Is this only a display bug of the region settings?
[regions.network]
installation_margin=10
rx_window=0
rx1_delay=2
rx1_dr_offset=0
rx2_dr=0
rx2_frequency=869525000
rx2_prefer_on_rx1_dr_lt=0
rx2_prefer_on_link_budget=false
downlink_tx_power=-1
adr_disabled=false
min_dr=2
max_dr=5
[[regions.network.extra_channels]]
frequency=867100000
min_dr=2
max_dr=5
[[regions.network.extra_channels]]
frequency=867300000
min_dr=2
max_dr=5
[[regions.network.extra_channels]]
frequency=867500000
min_dr=2
max_dr=5
[[regions.network.extra_channels]]
frequency=867700000
min_dr=2
max_dr=5
[[regions.network.extra_channels]]
frequency=867900000
min_dr=2
max_dr=5