Heart rate questions

Probably can't answer your question directly, but you will have different zones and maxHR for each sport.  Typically HRswim<HRbike<HRrun.  So, your biking and swimming may also be out of zone 2 too.  Or, your zones may be off based on the formula and estimate you are using.  The only real way to know is to test for each sport.  As far as maxHR, it is not a very expensive process (though can be a bit painful) as basically all you are going to do is increase effort as high as you can and see where you max out at.

Most people will advocate lactate threshold (LT) testing as a better way to measure your sport-specific zones, but testing for these is a bit more challenging and/or expensive.

For your run, how "slow" was this relative to how you would normally run?  Are you sure you could hold a conversation?  Did you try?  The reason I ask is that I know before using an HR monitor I was running at a pace I thought might be "conversational", but after slowing way down due to what the HR said I discovered what a real conversational pace is.  But is also quite possible that you were in that zone and your predicted maxHR is just off.