I think look at they overall point. How are you coming across on this thread?
People are explaining their points and experiences and you're digging your heels in, everyone else is wrong.
Now you're getting your mum involved.
I think you're a bit of a bull in a china shop socially and that can be very hard to shake once someone like that has got attached by accepting overture, favours, teas, whatever.
In general, English folk aren't unfriendly or unkind etc (some are!) but broadly, we are as independent as anything. We value freedom and not being stuck with obligations we don't want. We choose friends carefully, or a lot do. Many of us have deep social consciences, morals, humour etc. It's not that we don't love and care, but we are not as intertwined with others as some cultures. This isn't as simple as 'good or bad'.
I've had this discussion with many non native friends who find it lonely sometimes. I've said, just back off and let people get to know you in your own right. And slowly.
People are put off by those desperate for connection and friendship for its own sake. We can smell it a mile off and it smells like 'i will never shake this person off. They will never shut up and there may be a Scene'. God forbid a Scene.
If the working culture isn't about making teas or small talk, it's because people don't want that. Get to kn ow people and substantive conversations will form.
You could start a work social club and like minded people will gravitate. Lunchtime walks? That way you're doing it anyway. But A lot of people don't want to be jumped on just because they're there and you've got a loneliness issue. Manage that out of work.
I would find anyone really painful, telling me what to do out of work straight off the bat. That causes an obligation. I mean your old manager. You're still not grasping the cultural differences here. I'm sure she's lovely and I can see it coming up here if she happened to see an ad for an exhibition or whatever. That's fine. But its a fine balance and as I say, independence is key. Googling my interests? Back off.
Asking small talk questions when I may have difficulties outside work. You are coming across as really insistent and needy. People are very sensitive to that. I've worked in very chatty, fun workplaces. I've worked in very reserved , formal workplaces. All have been mostly great people. Not all ones I'd befriend but mostly decent. You have to read the room. You're getting people's backs up and pushing them away further by coming across as an obligation. You want to be someone that people want to have a quick chat with, or even go deeper. Give them space. Be professional. Say a breezy 'hi'. A joke here and there. I've always had really good friendships at work, whether they've endured or not. You can't push these though or engineer them. Let them happen at an equal pace.
I known someone who works for a big French company where they have to/ are expected to kiss on the cheek to greet colleagues (don't @ me, I don't know the full details and haven't been to the office but I believe them. It's a big company not some weird little setup in the back of beyond).
Would you prefer that? Honestly? Us fellow Brits aren't so bad. Just give us a bit of space, don't pry, don't try and create obligation, and let us get to know you. Don't force the issue. People can tell desperation. It's like opposing magnets.