For context: coparenting relationship is amicable. One shared DC. No other DC from other relationships. Both work full-time and I also run a business . I manage all the admin for DC. I take this responsibility because previously appointments would not be communicated or attended, for example.
Here's the issue: I communicate everything via WhatsApp in relation to DC. Appointments, school related things, etc. DC's dad expects to be reminded even though he has all the information on his phone, and gets annoyed when he fails to turn up for events, claiming that his memory isn't good.
AIBU to expect him to find a way to manage his time/memory? I make sure I physically write thinfs down and use my phone as a back up reminder. I don't have much more mental space to remind myself to remind him of things I've already communicated!