PPP lines not stable with NetworkManager

Hello All,

Im trying to upgrade from CentOS 6, I have configured ppp lines before with network-scripts and they work without any issues, but I am new to Network manager and I am facing couple of issues here.

My Setup - I have 4 ppp lines connected to my linux box and 4 vlans to connect to modem via a switch and I can bring them all up fine. There is script that monitors and runs health check every 15 mins and bounces them if required. This configuration works fine for a day or so and then all lines start acting weird and they wont come up at all unless I reboot the entire server then all lines start working. I have some logs that Im trying to debug and need some help.

eno2.101 - ppp0
eno2.102 - ppp1
eno2.103 - ppp2
eno2.104 - ppp3

When lines are down and I try to bring them up, I am getting below error -

nmcli con up DSLppp0

Error: Connection activation failed: The base network connection was interrupted

NetworkManager[2419034]: [1681376461.7138] audit: op=“connection-activate” uuid=“a436a203-0750-33d7-a798-3e0eceb5d37a” name=“DSLppp0” result=“fail” reason=“Failed to find a compatible device for this connection”

//Interfaces like ppp42 which is not configured anywhere shows up in logs as well.
NetworkManager[2879665]: PPP session is 21561
NetworkManager[2879665]: Connected to 00:1e:13:c2:89:c3 via interface eno2.103
NetworkManager[2879665]: using channel 8848
NetworkManager[2879665]: Using interface ppp42
NetworkManager[2879665]: Connect: ppp42 ↔ eno2.103
NetworkManager[2879665]: sent [LCP ConfReq id=0x1 <mru 1492> <magic 0x90f82ba5>]

here my NM config for ppp0, similarly we have for ppp1,2,3

cat DSLppp0.nmconnection







For some reason pid file not taking into affect even if manually touch that file it will get deleted.
ls -lt /var/run/pppoe-adsl-0.pid
ls: cannot access ‘/var/run/pppoe-adsl-0.pid’: No such file or directory

These same lines are working fine with centos 6 and laptop as well. Not able to figure out where the issue is any help is appriciated.