it is always hard to answer these questions since you are playing a heavily modded version, so difficult to say if the issue is with the game or the mod.
The AI in SH5 has 3 states: "passive" it does not know you are there (small detection circle), "alert" it suspects something is there, but has not detected you (larger detection circle) and "detection", you are spotted and all escorts are gunning for you (largest detection circle). By turning on detection circles in the settings, you should get a better idea what the issue is.
The other problem is that you are running "decks awash", presumably the deck is underwater and only the conning tower sticks out. The issue there is that the game treats your sub as if you are underwater so the AI will never "see" you, it can only detect you through its hydrophones. Running decks awash is a gamey tactics that the Devs never anticipated so results in game may be strange.
If you still feel you are being detected too far out, the issue may be with the sensors or sim.cfg which you could modify or revert to the stock ones although that may require some digging in the files to see what was modded.
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