Cyrtocidium with black spots, or virus

[Matorchid]

Hello all,
Have another question about one of my Onc mixes, I think he relapsed.
Purchase this guy late April and he can in with small tiny black spots. treated him for three weeks with Natria and all seem to be well and good. I got two spikes on him already with just a couple flowers but all black as can be. I must have sat him to close to the window and he got a sunburn. Well it's a couple days now and his black spots have reemerged to become black rings and quite large. I'm wondering if I should have some concern for this! I guess under stressful circumstances these guys can bring a virus back is the way I understand it, like it lays dormant until something happens, not sure if I have that info right. So I was wondering if any of you had any input all would be appreciated

Thank you in advance
Matorchid