uBR10K upload speed test won't run. Intermittent service reported by customers

Hi Folks,

Has anyone experienced this before with Cisco uBR10K.
I've had to roll our customers back to Casa C2200.
The modem levels are fine, no errors but looks like upload is throttled or there is a delay allocating upload slots.
I just need 2 x bonded downstreams and 1 upstream. No upstream channel bonding.

My config is as follows:

controller Integrated-Cable 8/0/1
rf-channel 0 cable downstream channel-id 173
rf-channel 0 frequency 285000000 annex B modulation 64qam interleave 32
rf-channel 0 rf-power 54.0
no rf-channel 0 rf-shutdown
rf-channel 1 cable downstream channel-id 174
rf-channel 1 frequency 291000000 annex B modulation 64qam interleave 32
rf-channel 1 rf-power 54.0
no rf-channel 1 rf-shutdown

interface Cable8/0/1
description ""
downstream Integrated-Cable 8/0/1 rf-channel 0-1 upstream 0-1
no cable mtc-mode
no cable packet-cache
cable default-phy-burst 4096
cable bundle 2
cable upstream max-ports 4
cable upstream ranging-poll interval 25000
cable upstream 0 connector 4
cable upstream 0 frequency 28300000
cable upstream 0 channel-width 3200000 3200000
cable upstream 0 ingress-noise-cancellation 10
cable upstream 0 power-level 3
cable upstream 0 description "South 285MHz BLUE"
cable upstream 0 docsis-mode tdma
cable upstream 0 minislot-size 4
cable upstream 0 range-backoff 3 6
cable upstream 0 modulation-profile 21
cable upstream 0 equalization-coefficient
cable upstream 0 rate-adapt priority 6 rate 30000000
no cable upstream 0 shutdown
cable upstream 1 connector 5
cable upstream 1 frequency 37900000
cable upstream 1 channel-width 3200000 3200000
cable upstream 1 ingress-noise-cancellation 10
cable upstream 1 power-level 3
cable upstream 1 description "South 291MHz GREEN"
cable upstream 1 docsis-mode tdma
cable upstream 1 minislot-size 4
cable upstream 1 range-backoff 3 6
cable upstream 1 modulation-profile 21
cable upstream 1 equalization-coefficient
cable upstream 1 rate-adapt priority 6 rate 30000000

interface Integrated-Cable8/0/1:0
cable bundle 2
cable rf-bandwidth-percent 50 remaining ratio 100
!
interface Integrated-Cable8/0/1:1
cable bundle 2
cable rf-bandwidth-percent 50 remaining ratio 100

interface Wideband-Cable8/0/1:1
cable bundle 2
cable rf-channel 0 bandwidth-percent 50
cable rf-channel 1 bandwidth-percent 50

cable fiber-node 2
downstream Integrated-Cable 8/0/1 rf-channel 0-1
upstream Cable 8/0 connector 4-5

Thanks,
Chris.