This is on the same catt that's having a fungus problem. However, the spots on this particular leaf looks quite different. As you can see in the pic, one spot is a circle and another is a dot with a half circle. I'm getting nervous, in fear that it might be a virus. What do you think? Does it look suspicious? (If you think it "could" be a virus, I might have to get a virus test...)
Doesn't look at all like a virus to me.
Looks more like damage from insect or possibly early rot.
If the spots are firm and dry, it is probably not a worry.
If the spots are soft, cut the leaf off one inch into clean tissue.
If my catts have lots of "good leaves" I don't sweat pruning leaves that have questionable garbage on them.
To be quite frank however, if these spots are dry and hard I would not worry.
Looks like a fungal spot to me - probably due to water droplets standing on the leaves as the cool of evening comes.
As you have a systemic fungal issue with a catt, and now this, I think a good soaking with Physan to clean up the background load of fungus in your growing area may be in order, and you might think aboout your watering habits a bit to allow complete drying.