Zwift Power Category Confusion

Took part in FZR Masters Race this morning, entered my correct category, D, and raced. On completion Zwift Power has registered my category as H, and an individual I raced against who was also in D, has been listed as G in Zwift Power.

Can someone please explain what is happening here?

Looks like this event has age-based category split

You crushed the 65-69 age group. If you click on Description for the event, it explains how it works:

FZR offers a weekend race where you could race against each others in your own age group.
Race lengths are about 1.5 - 2.0 hour with variety terrain.
Please, select a correct starting pen based your own age. (use year number how old you will be at the end of current year)
Note. Results are splitted to UCI age groups after the race in ZwiftPower. (https://zwiftpower.com)

Race pens: (system max 5 pens)
A = 30-39
B = 40-49
C = 50-59
D = 60-69
E = 70-**

Result age groups: (system max 10 pens)
DQ < 30
A = 30-34
B = 35-39
C = 40-44
D = 45-49
E = 50-54
F = 55-59
G = 60-64
H = 65-69
I = 70-74
J = 75-**

Thank you for clearing this up Paul.