I'm currently in Canada with work and can't use social media apps, it's intermittent. WhatsApp, Snapchat and Instagram etc. Tried reseting network settings, restarting the phone, changing network carrier and all the right settings are on but nothing changes
If data is a must have your only option is to get a local sim card but you'd have to divert calls to it from your O2 number.
I have no affiliation whatsoever with O2 or any subsidiary companies. Comments posted are entirely of my own opinion. This is not Customer Service so we are unable to help with account specific issues.
Currently using: Pixel 7a (O2 & Lyca), One Plus 6 (Sfr), iPhone 12 Pro Max (Vodafone)