as @ClockworkOcean said, the boolean operation resulted in a topology that won’t allow for the edge loop to find a path. There are a couple options you could do to resolve this. The first option would be to control the topology from the begining by using edge loops in combination with extrude type operations so that your topology maintains quad polygroups.
The second option would be to use edge insert to split the front face into two quad polygroups.
You can then use insert loop to add edges where needed. Also it’s a good idea to switch the loop insert to “retopolgize” instead of plane cut it can really help keep the triangles clean.
Cheers,
R