Internet not working

I was on Vodafone and chose to switch to LEBARA as it was a lot cheaper. I understand LEBARA uses Vodafone signal but I can’t seem to get the internet to work. I’m using dual sim atm so if I switch to Vodafone sim the internet works perfectly. Anyone else had these issues?

Is the correct Access point setting selected.

Hi, for us (Ealing, London W5 area) mobile internet dramatically dropped on the 17th of January. Screnshot attached and shows how good it was prior to that date, and how poor it turned to be.
Since then I talked to Lebara Customer Service twice, for example on the 21st talked them for 31 minutes. They asked about our phone make, settings. Explained them we didn't touch any settings, their service had cut down on my wife's phone too. APN settings double-checked, phones restarted, toggled with airplane mode, etc... Emailed them screenshots too.
Lebara neither came back to us nor solved the issue. It is the 10th day today!