Coolant overflow tank empty

So this problem I just noticed has me baffled. I noticed the coolant tank was low, near empty one day and filled it withing the limits. Then after a few days of driving I checked again and my engine looked like it has been sprayed by coolant ( had all these white dry water/coolant marks everywhere) and the coolant overflow tank was near empty again. I did this 2 more times and same thing.

Then the last time I filled my overflow tank to within the limits, cleaned the engine to see if this problem returned. Now the engine doesn't look like it has been sprayed by coolant anymore but today when I checked the overflow tank was low again.

What could be causing this problem? There are no visible bubbles in the radiator while the engine is idling, the compression is 225 across all 3 cylinders by the firewall and 230,225,235 across the front ones. The difference between the highest and lowest comp. numbers is less than 5%, which is well within the tolerance limits. The oil clean and not milky, doesn't look like it's getting water/coolant in it. These observations would lead me to rule out a head gasket issue, but for some reason, I still think it could be the headgasket since the coolant has to be going somewhere now since it's not being sprayed on the engine anymore... Any help is greatly appreciated. Thanks for reading