LimeSDR’s maximum transmitting power at different frequencies

For the maximum transmit power (CW) for LimeSDR, the output power I measured (using a power meter) is close to 5dBm at 1 GHz when using TX output 1. Furthermore, my maximum transmit power for my LimeSDR is consistently 10dBm under what your graph shows. Any ideas as to why? Also, is this something I should be concerned about?