Hi Halo,
Greetings, I am afraid that your device is not in the default mode as all ports are supported as access or uplink ports, but cannot be channelized.
It looks like you are using the Flexi-pic-mode in which ports 20 through 27 are disabled.
Can you issue this command and check?
show chassis system-mode
Now if the mode is default can you reboot the device, it is recommended by Juniper.
NOTE
When you request the system mode change, we recommend that you reboot the switch for the system mode to take effect.
If the mode is flexi-pic you can change it doing this:
request chassis system-mode default-mode
request system reboot at now
Please keep in mind the following before/while doing any changes :
CAUTION
Changing the system mode causes the FPC to reboot. Because there can be a slight loss of data while the FPC reboots, we recommend that you only configure the changes during a maintenance window for this release.
CAUTION
Take care when changing the channelization mode from Flexi-pic to default. If you have existing ports that are channelized in Flexi-pic mode, remove the channelization from the interface before changing the system mode. Changing the Flexi-pic mode to the default mode with channelized ports causes the ports to go down, log a system log error, and remain down. You must manually remove the channelization configuration on the ports to bring the ports up in default mode.
Official doc: https://www.juniper.net/documentation/en_US/junos/topics/topic-map/switches-interface-port.html#id-configuring-the-system-mode
If this solves your problem, please mark this post as "Accepted Solution" so we can help others too \:)/
Regards,
Lil Dexx
JNCIE-ENT#863, 3X JNCIP-[SP-ENT-DC], 4X JNCIA [cloud-DevOps-Junos-Design], Champions Ingenius, SSYB