How to configure return route S4128T-ON (OS10)

Hi,

I have two S4128T-ON (OS10) switches connected with VLT.

These two switches are connected to two other switches with LACP in our datacenter to provide internet access and external connection.

The VLT connection was being performed using VLAN.

The recommendation for VLT communication is that it be done via the management port. We made all the IP settings on the management ports, reconfigured the VLT to use the management ports successfully.

However, when we connected the cable to the port and management between the switches, at that moment we lost access from the routed network to the two IPs of the swtiches that was working.

Before we were able to ping the IPs (172.16.10.5 and 6) of the routed network switches (172.17.10.0), now not anymore.

The network team's recommendation is to add one (next hop) on the switches for the network (172.17.10.0/16) to (172.16.10.1).

Doubts:

1 - Why did this work before we connected the cables between the switches?

2 - How do I add this (next hop)?

3 - Is there a risk of something crashing if I add this (next hop)?

Thanks.