I've recently upgraded to version 22.214.171.124 on TP Link TL-WR1043ND (v2). After the upgrade I immediately noticed a significant drop in WIFI range so started to investigate the WIFI settings. When I upgraded I noticed that the WIFI region was set to US and the Transmit power to auto which meant that the TXPower was set to 25DBM (which I believe exceeds the European limit).
I set the setting to the region where I live (Spain: ES) and noticed that although I get the option to specify a Transmit Power up to 20dbm the TXPower in the WIFI status will never exceed 14dbm. If I set the region to US and choose 20DBM the setting is respected.
From reading some threads on the forum - it seems this might be because Openwrt is taking into account antenna gain (and hence dropping the transmit power so as the total EIRP is not exceeded), but I'm not sure if I'm on the right track as 14dbm seems like it might be low even taken into account antenna gain using stock antennas?