Hassio querying api.macvendors.com thousands of time

I run a pihole instance on a dedicated Pi, and ive noticed that Hassio (on a different Pi) is making thousands of queries to api.macvendors.com.
It seems to be making this call every 10 secs, every hour of every day. This is best case, quite often it ramps up to once every 3 - 5 seconds!
Is it normal?
I have done some digging and as far as i can see none of the integrations etc. i am using would need this.
Does HA core itself use it? And is it really neccessary to query it every 10 seconds, none stop?

Or can anyone give eny tips on trying to find the guilty party (ideally without having to disable everything, and re-enable one by one and so on)

I don’t see this in my pihole logs, so I guess it is coming from a integration
do you have something special regarding networks?

Nope, I have a very small HA ecosystem.

The only network related integration is the pihole one to retrieve stats.

Other integrations are:
Garbage collection
Google Cast

Little update, changed logging level for the device tracker component and see the below occuring many times.
No idea if it’s relevant

Logger: homeassistant.components.device_tracker
Source: components/device_tracker/legacy.py:320
Integration: Device Tracker (documentation, issues)
First occurred: 27 January 2021, 15:47:35 (1220 occurrences)
Last logged: 5:46:48

Updating device list from legacy took longer than the scheduled scan interval 0:00:12

Another thing I’ve spotted…

I have a lot of entities device_tracker.unknown_x
More than 20, plus the ‘known’ entities I have named using known_devices.yaml

I’m using the Sky hub tracker component

Any help would be appreciated