First Situation:
With a new coworker, you get off to a bad start.
They ask for your assistance in responding to a customer question, but you decline because you are on a tight schedule and don't want to waste time. Since then, there's been a lot of friction between you two, and now you need their support on a project, but they're not responding well.
Solution:
Take control of your situation! When the time is right, approach them and say, "I understand that we got off on the wrong foot." Please accept my apologies. X is the problem I'm trying to solve. Should we have a discussion about that?
Regardless of who you're in disagreement with - an employee, your supervisor, etc. - if you show self-awareness, they'll think more highly of you. Even if the conversation is uncomfortable, it's preferable to a strained relationship that might last years because you started out on the wrong foot.
Second Situation:
You're annoyed because your French colleague keeps texting you at 5 a.m. (your time). They give you urgent requests when you're sleeping or just waking up, and you're tired of getting 11 requests before you've even sat down at your desk. You get the impression they don't like you and you're not sure how to handle them.
Solution:
Avoiding conflict is only making things worse, not better! Make a time to talk with them over the phone or via video call.
Uncover the root of the problem by asking questions "Is there any particular reason you send me requests before I'm up? Am I responding to you too late?
Once you understand why they're doing it, you can help them articulate their needs. Maybe they send you 11 messages at 6 am because that's right before their lunchtime, and they don't want to forget their questions when they go on break.
Now figure out a solution that works for both of you. Can they send themselves a reminder on Slack to ping you with their questions when you're at your desk? Can you just ignore their messages until you clock in now that you understand they're not time-sensitive? Should you schedule a morning check-in to go over these requests in real-time rather than via message.