I have set these values on SXT SA:
antenna-gain=14 band=5ghz-onlyn country=austria dfs-mode=radar-detect disabled=no frequency=5600 frequency-mode=regulatory-domain mode=ap-bridge wireless-protocol=nv2

Now current Tx power stays on 3/6dBm (+14dBi = 20dbm = 0,1W)

Without dfs-mode current TX power stays on 10/13dBm (+14dBi = 27dBm = 0,5W)


It seems that there is something wrong, we are allowed for up to 1W when using DFS in this frequency range: https://www.rtr.at/en/tk/Spektrum5GHz


Any ideas?

I don't believe DFS in taken into consideration for the auto power adjustment, just the country, band, and antenna gain. Try setting the power manually or adjusting the antenna gain to account for the difference.