EU Roaming suddenly very slow

[#1]

Hello.

I am in Germany at the moment on a goodybag that gives me 5GB of mobile internet. Yesterday, my internet connection suddenly went really slow (down to GPRS from 3G). I have previously used my phone in Germany and in other EU countries at that hasn't happened before. I have been in the exact same city, I even headed into the city centre just to see if the connection might be better there -- nope. After a couple of restarts (unsuccessful) I turned my phone off last night and only turned it on again this morning. Still only GPRS. 

My friend who I am staying with is on the same network (O2), but as a local German user and has no problems whatsoever so it doesn't seem to be an issue with the network itself.

I have also checked the APN settings -- all as indicated on the website. 

Data roaming is turned on. 

Would you be able to help? Obviously being on GPRS is extremely annoying as it is painstakingly slow...

Thank you.

[#2]

Try going into the phone settings and clear the web history and cache then restart the phone to see if that helps.

[#3]

@felixbrender

Some local carriers actively throttle roaming SIMs.

It shouldn't be that way but if the situation does not improve after a restart then there is little that you or giffgaff can do about it.

That said, you might to try selecting an alternative local carrier manually from your phone.

Normally you do this in Settings>Network>Network Selection

[#4]

Thank you to both of you for your answers.

I tried clearing the cache first but that didn't help; nigelbrooks is spot on, I think. It's O2 that is throttling my internet speed.

Having tried to select another carrier as you said, though, I find that I have no connection at all -- that might be because giffgaff have an agreement that allows me to only use their network while in Germany.

Well. At least now I know; it's something to keep in mind in the future

Thank you!