Itโs less likely to spread thru the air. Itโs mainly transmissible by hands, tools, or even by certain โchewingโ style bugs like caterpillars or grasshoppers. Itโs in the sap. So just clean everything and touch the plant as little as possible ๐ฑ
Looks more like a ph issue to me. If you have been watering/feeding at 6 ph, that is the low end for soil. 6.5ish is better for soil. The soils ph may have dropped even lower than 6 which starts creating problems. Check your soils ph level.. Cheers