Too much sun or is it a virus, Physan 20

[Jim S]

Attached are pics of a cymbidium, I believe the brown circles on the leaf tips are from sun exposure - could they indicate a virus? The remainder of the leaves look good.
Plant is growing nicely.

Also attached is a pic of a miltassia with brown leaf damage at the base. The remainder of the leaves look good, the orchid seems to be growing a little slow.
Did a bug/bugs do this? I'll see a fruit fly once in a while around the orchids.

I recently got back into orchids after 25 years... I'm very watchful (yes, you can say paranoid) for overwatering, bugs and viruses, my orchids are growing very well. Before potting I flush the medium with Physan 20. It's been about a year since I've used Physan 20, does anyone just flush out their potted orchids with this or a similar product periodically as a matter of procedure?

Thanks for your help, it's appreciated.