Ssh Tunnel via Multiple Hops: Connection Refused

i have 4 linux VPS and one Windows Client.

i want tunnel client to VPS-4 :

client -> VPS-1 -> VPS-2 -> VPS-3 -> VPS-4 -> internet. i use the command in Windows OS CMD :

ssh -D9999 root@VPS-4-IPaddress -J root@VPS-1-IPaddress,root@VPS-2-IPaddress,root@VPS-3-IPaddress

after command i enter all VPS password . Everything works fine and work good in first , But I have two problems :

1- After a few minutes or an hour I see the following error :

channel 23: open failed: connect failed: Connection refused
channel 24: open failed: connect failed: Connection refused
channel 3: open failed: connect failed: Connection refused
channel 10: open failed: connect failed: Connection refused
.
.
.

2- Sometimes the connection is lost after a few hours :

client_loop: send disconnect: Connection reset

In either case, I have to enter commands from the beginning each time .

any advice for this?