Paphiopedilum Rotschildanum Brown spot

[Tomas96]

Hi Everyone!
I have an issue with a paphiopedilum rotschildanum I’ve purchased online recently.
The orchid arrived in bad conditions already, completely out of the bark and with an injured leaf.
I’ve quickly repotted the plant using a mixture of bark, perlite and sphagnum moss.
I’ve located the plant in an outdoor cool greenhouse with a minimum of 90% of humidity and temperatures around 20 max to 15 minimum at night.
The light is really high but not direct sunlight
I don’t let the plant pot never dry out of course.
Just few days later I’ve noticed a brown spot on the youngest leaf, with a light green to yellow halo around.
Do you think that is just something I can not worry about or it is a kind of disease?
Thank you so much for your help!