Your English is excellent! The DD in some of the groups are set to a lower 'efficiency' setting, while some are set higher and able to track your boat much more easily, but this is at an individual ship level, and not global, as the CFG file would control. In other words, some escorts are smart, some are really smart, but the one you found, not so much. A single escort should be out front, in the lead for a convoy, but if the crew of the escort is not highly skilled, they won't do a very good job...
They battery recharge time is apparently another one of those settings in the game that when changed, will adversely affect other systems, and we may have to leave well-enough alone, since it seems to affect engine power, which affects boat speed and diving times. There are more tests to run through, and we'll leave the details for more-highly qualified team members to explain. This is another one of the frustrating aspects of the game engine...
The player not hearing ships on the sonar station is frustrating, and has been worked on and improved for the next release. Again, I'll leave the explanation for others to tell.
Airplanes and their 'skill' level is, to an extent, a matter of preference. Some like more, some like less. We're attempting to hit the middle ground target, and might be able to make an add-on mod for players to "tune" the airplanes's frequency & accuracy to the player's liking, in conjunction with overall AI mods...
