Little advice on where to start with this mystery

Here’s my issue folks. Started out temp reading like 39 degrees while driving. Read fine standing still. Found temp sending harness was rattling off & fan wasn’t kicking on. Fixed that, drove fine for a bit, at the end of my ride it started spitting antifreeze from the hose at the top of radiator (near overflow). Thought I kinked hose. Drove fine for 2 all day rides. End of 2nd ride got a message on screen "lo" & spitting antifreeze again. Not as much, but still. Wondering where to start. Can’t make it do it again in the garage.