Unsure what frogs you have in there and their requirements. Mats are not efficient; but only 1C degree difference seems low. Does mat feels hot when you touch it? Have you tried covering screen areas with saran wrap (taped to tops edge) or polycarbonate plastic sheet cut to size to reduce heat loss? If doing so, just keep it away from heat sources by 1 cm. or so.
Mat feels hot, not much cause is tropical mat. Yes, I could cover with saran wrap. Maybe I get to balance the lost of humidity because of the heat.
Sounds like you installed it right.
Don't understand this sentence. In my opinion bulbs heat better than mats. If you do not have a light fixture getting one will help raise temperature in enclosure. If you tell us the type of enclosure and size, maybe we can make recommendations. If using to heat, try to get either red or black bulbs so you can use them 24 hours on without disturbing frogs. Good luck

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