2017 CRV Touring - Pearl White w Black Interior
And I bet the immobilizer got activated when the battery was swapped out... probably by a momentary spark from positive to ground glitching the power rail on the immobilizer circuit. In which case the best practice as most of us here have learned is to disconnect the battery for 10 minutes to allow every single circuit in the vehicle to loose stand-by power and hence fully reset when they are repowered up by reattaching the battery.For someone claiming not to be a dummy, you dont exactly seem clued up on how a weak battery affects all the electrical systems.
The reason(s) why every warning displays is because the car is telling you something is wrong. Read the manual - your answer lies within.
Could also be the immobilizer triggered due to something not battery related at all. That can happen.