Mobile hotspot very slow despite LTE. How so?

I have an O2 Free Unlimited Max contract, i.e. LTE and unlimited. After a few speed tests, the speed on my mobile phone is 25-40 in the download and 16-25 in the upload. The speed on my laptop is slightly slower (always over 10), just like on my Ipad.

Nevertheless, I can't carry out video conferences via the hotspot e.g. On my laptop, even if I take the Ipad off the network and there's no activity on the cell phone. And there's also a lot of speed (min. 10mbits), which should be enough. Now I wonder why this is not as fast as the speed test on the laptop shows.

Is that possibly due to the Sim card?

Mobile phone: Samsung S9

Laptop: old Asus

Ipad: Pro 2020

! Problem exists on laptop and Ipad, it is most likely not due to either device)

A download from 25 to 40 seems to me for z. B. Interference-free streaming borderline or already too low. Since you would have to conclude a contract with better performance or go via cable or VDSL. I know this doesn't really help you.

This contract is the maximum at O2. Sometimes I also have 60Mbits (although it says up to 225mbits), and then 30 arrive at the laptop. Then it still doesn't workFor video conferences, it rarely needs more than 4mbits for 5 people. And that's pretty much exactly my activity. With over 10 it should work out rather 20.

It works fine on the cell phone, just not via the mobile hotspot