Simple load balancing across Cisco port channel?

I don't tend to get too in-depth on Cisco stuff so knowledge is lacking there. We have a Cisco 2960 rack-switch with 2x 1Gbps uplinks to a Juniper MX gateway.

We have 3 devices on this switch running around 300Mbps up and down consistently, and many other devices with far lower traffic i.e. >10Mbps.

Inbound is fine and can burst to over 700Mbps but Outbound isn't doing so well and is mostly going over one port, causing other devices to suffer from low outbound speeds.

How can I get the outbound traffic balancing over the two ports better?

Only config relevant to the trunk ports below.

interface Port-channel1

switchport trunk allowed vlan *****

switchport trunk allowed vlan add *****

switchport mode trunk

spanning-tree bpdufilter enable

!

interface GigabitEthernet0/47

description po1

switchport trunk allowed vlan ***

switchport trunk allowed vlan add ***

switchport mode trunk

no cdp enable

channel-group 1 mode active

!

interface GigabitEthernet0/48

description po1

switchport trunk allowed vlan ***

switchport trunk allowed vlan add ***

switchport mode trunk

no cdp enable

channel-group 1 mode active

The two uplink ports below:

https://i.imgur.com/wS1gMZD.png

https://i.imgur.com/cTFjwxj.png

Thanks in advance!