Two connections to one VPN Mikrotik. Why does the second connection fall off?

Question

VPN

I have a Mikrotik HAP2 router. It has a l2tp+ipsec VPN server. Two computers are connected to it from another subnet through the TPLink Archer C5 Router under different logins (secrets). When only one is connected, everything is fine. As the second client connects, the first falls off. If clients are connected from different subnets, then everything is OK. Why is that?

Answer 1

AFAIK, Mikrotik IPSEC is tied to the ip addresses of clients. At least he ties politics to them.
and since they are from the same subnet, then Mikrotik at the IPSEC level sees them the same way.

Answer 2

the problem here is that two l2tp from the same address, and not ipsec, tk. ipsec is already inside l2tp , it is
better to switch to openvpn if you really need two connections

Answer 3

There is a solution, but it is, to put it mildly, not very trivial, and I would not recommend it even to a fairly qualified network specialist.
https://forum.mikrotik.com/viewtopic.php?t=132823
It is better to change the vpn type to pure ike2 (problems are possible if you use ospf) or to sstp.
Or, if on a remote client network, several use a site-2-site VPN.
Well, or in the forehead, openVPN, but I try not to use this type of vpn connection for many reasons.