Can't detect monitors connected to Dell WD15

I have a HP Envy 13 (ad012na) running KDE Neon 18.04 (Ubuntu 18.04 with KDE) which can't detect the monitors (2x Dell U2414H) connected to my Dell WD15 dock via DisplayPort. The second monitor is daisy chained. I have tried the following to debug:

1. Connect a single monitor via DisplayPort (failed)
2. Connect a single monitor via HDMI (failed)
3. Connect my wife's HP Envy 13 (ad012na) running Windows 10 (works)
4. Connect my Dell XPS 13 running Ubuntu 18.04/20.04 (works)
5. Connect a Vanmass ARAZ21 USB-C hub with an HDMI port (works)
6. Connect my HP laptop using a Ubuntu 20.04 live disc (fails)

So it seems the issue only occurs when I use my laptop running a flavour of Ubuntu to the Dell WD15 dock. Below are the outputs of xrandr for my Envy laptop and my XPS laptop:

Dell XPS 13 (Ubuntu 18.04/20.04):

Screen 0: minimum 8 x 8, current 4920 x 1920, maximum 32767 x 32767
eDP1 connected 1920x1080+3000+644 (normal left inverted right x axis y axis) 290mm x 170mm
1920x1080 59.93*+ 59.93
1680x1050 59.88
1600x1024 60.17
1400x1050 59.98
1600x900 60.00 59.95 59.82
1280x1024 60.02
1440x900 59.89
1400x900 59.96 59.88
1280x960 60.00
1368x768 60.00 59.88 59.85
1360x768 59.80 59.96
1280x800 59.81 59.91
1152x864 60.00
1280x720 59.86 60.00 59.74
1024x768 60.00
1024x576 60.00 59.90 59.82
960x540 60.00 59.63 59.82
800x600 60.32 56.25
864x486 60.00 59.92 59.57
640x480 59.94
720x405 59.51 60.00 58.99
640x360 59.84 59.32 60.00
DP1 disconnected (normal left inverted right x axis y axis)
DP1-1 disconnected (normal left inverted right x axis y axis)
DP1-2 disconnected (normal left inverted right x axis y axis)
DP1-2-1 connected primary 1920x1080+0+372 (normal left inverted right x axis y axis) 530mm x 300mm
1920x1080 60.00*+ 50.00 59.94
1600x1200 60.00
1600x900 60.00
1280x1024 75.02 60.02
1152x864 75.00
1280x720 60.00 50.00 59.94
1024x768 75.03 60.00
800x600 75.00 60.32
720x576 50.00
720x480 60.00 59.94
640x480 75.00 60.00 59.94
720x400 70.08
DP1-2-2 disconnected (normal left inverted right x axis y axis)
DP1-2-2-1 connected 1080x1920+1920+0 right (normal left inverted right x axis y axis) 530mm x 300mm
1920x1080 60.00*+ 50.00 59.94
1600x1200 60.00
1600x900 60.00
1280x1024 75.02 60.02
1152x864 75.00
1280x720 60.00 50.00 59.94
1024x768 75.03 60.00
800x600 75.00 60.32
720x576 50.00
720x480 60.00 59.94
640x480 75.00 60.00 59.94
720x400 70.08
DP1-2-2-2 disconnected (normal left inverted right x axis y axis)
DP1-3 disconnected (normal left inverted right x axis y axis)
DP2 disconnected (normal left inverted right x axis y axis)
VIRTUAL1 disconnected (normal left inverted right x axis y axis)

HP Envy 13 ad012na (Ubuntu 20.04/KDE Neon 18.04):

Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 16384 x 16384
eDP-1 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 294mm x 165mm
1920x1080 60.01*+ 59.97 59.96 59.93 40.00
1680x1050 59.95 59.88
1600x1024 60.17
1400x1050 59.98
1600x900 59.99 59.94 59.95 59.82
1280x1024 60.02
1440x900 59.89
1400x900 59.96 59.88
1280x960 60.00
1440x810 60.00 59.97
1368x768 59.88 59.85
1360x768 59.80 59.96
1280x800 59.99 59.97 59.81 59.91
1152x864 60.00
1280x720 60.00 59.99 59.86 59.74
1024x768 60.04 60.00
960x720 60.00
928x696 60.05
896x672 60.01
1024x576 59.95 59.96 59.90 59.82
960x600 59.93 60.00
960x540 59.96 59.99 59.63 59.82
800x600 60.00 60.32 56.25
840x525 60.01 59.88
864x486 59.92 59.57
800x512 60.17
700x525 59.98
800x450 59.95 59.82
640x512 60.02
720x450 59.89
700x450 59.96 59.88
640x480 60.00 59.94
720x405 59.51 58.99
684x384 59.88 59.85
680x384 59.80 59.96
640x400 59.88 59.98
576x432 60.06
640x360 59.86 59.83 59.84 59.32
512x384 60.00
512x288 60.00 59.92
480x270 59.63 59.82
400x300 60.32 56.34
432x243 59.92 59.57
320x240 60.05
360x202 59.51 59.13
320x180 59.84 59.32
DP-1 disconnected (normal left inverted right x axis y axis)
DP-2 disconnected (normal left inverted right x axis y axis)

I'm at a loss as to what to try next. I can post the output of any commands required to debug this. This entire setup is borrowed from my work while I'm stuck at home, but I was strongly considering buy the exact same dock and monitors as I really like my work setup. Unfortunately since I can't get it to work with the HP Envy I'm probably going to have to look for a different set up.