How to create permanent connection (keep alive) with "IPFS swarm connect"

[nk-the-crazy]

IPFS version: 0.4.20

To speedup content discovery, creating connection to source peer
( via "ipfs swarm connect /PEER_MULTI_ADDRESS". ).
Connection is succeeded but why it is disconnecting unexpectedly (connection is alive for max 10 - 40 secs). I assume, this issue was solved in 0.4.20 (by marking it as "important").
Or Am I missing something ?

[obo20]

The fix you're referring to unfortunately doesn't work. See: #6271