Problem with new outbound connections failing

[obstler42]

I just recently switched over from pfSsense as I saw and like the more open and active development of opnsense.

Now I have a Multi-Wan setup with a DSL line and and LTE modem. Wan (1) with DSL works fine just as expected. But I have severe problems with the LTE modem. It is a Netgear LB1111 in bridge mode on WAN2. Already had another thread because of the DHCP settings on the LTE modem causing problems in opnsense, because the netmask was set to /32 and the gateway was x.x.x.1 and therefore outside the subnet. That was fixed by using static IP4 settings.

However the LTE line causes problems whenever a new connection (like opening a website in the browser) fails like 2 out of 3 times. I have no idea what causes this, tried looking at the firewall diags and found it strange that both state stats and state dump are completely empty.

Is there a way to trace problems like that (maybe from the command line)?

the same setup (dsl and lte) was working fine for years on pfsense, but I would really like to switch over and stay with opnsense.

edit/update with more info:

long standing connections work just fine (like a webradio stream plays fine for hours), but new connections fail quite often: just clicking on different articles on a webpage fails to connect or times out a lot.

I don't know if it's a problem with the LTE modem or the LTE "line", as I don't have another LTE modem to test with. The problem occurs whenever the LTE line is active: in multi-wan and also when I disable the DSL line and have only the LTE gateway active.

dpinger/gateway logs don't show anything out of the ordinary.

DId some more testing and the problem also occurs with only the DSL line active, but just less often. Like 1 out of 5 or 10 connections fail.

All this is with a new 19.1.4 setup (also tried the update to 19.1.5_1, same results).