If you are observing a TAT temperature, as indicated by your aircraft gauges/displays, that is higher than expected, please be aware that TAT is not the same as OAT or SAT.
TAT is expected to be higher than OAT/SAT especially in faster aircraft including jets. The reason is RAM RISE which is essentially due to heating affect of the air as it compresses when contacting your aircraft and associated temperature/air sensors. In jets, TAT temperatures of 15C+ or more over OAT/SAT are normal when at cruise altitudes/speeds.
Here is a nice article on the web that explains this in more detail: https://www.flyingmag.com/air-temperature-explained/.