So basically my problem is the following: after I suspend my notebook and resume my internet gets really laggy, for example sites take much longer to load or fail to load, twitch.tv cannot properly buffer video, etc. I also performed a speed test (ookla) and the results were 4 times less than my normal speed (it was 16Mb to local provider when my normal rate is 100Mb) and even so, when I monitor my connection through iftop it's usually like 200kb after resume. Also I checked ping and it reported 0-5% package loss without almost any 'time' changes.
The only thing that helps is rebooting my router, which is really weird. I also tried: rebooting the notebook, restarting NetworkManager.service, dhcpcd.service, reconnecting via GUI, disconnecting my Ethernet->usb dongle and connecting it back with service restart but to no avail.
I tried looking into journalctl and dmesg but didn't see any relevant info. I have seen a few ipv6 errors, hence tried disabling it, but it didn't help. I've had this problem for a week or so now, maybe some package update just broke it but not sure.
Also, I've had a few (rare) situations where kernel just froze (task scheduler blocked for more than 120 seconds) where I couldn't do almost anything, not even shutdown properly. Looking through logs later on it seems to me that network drivers were involved (based on stacktrace in logs), maybe even dongle drivers because one time it happened when I was messing around with my connection.
Asus zenbook 16GB RAM, i7-7700hq, 1050ti but no drivers installed and nouveau blacklisted (I use intel graphics because X server couldn't load properly with either nouveau, nvidia drivers or bumblebee) with Arch linux + KDE + SDDM
Internet connection via Ethernet->Usb dongle
dongle: 0bda:8153 Realtek Semiconductor Corp. RTL8153 Gigabit Ethernet Adapter) uname -a Linux neko 4.15.14-1-ARCH #1 SMP PREEMPT Wed Mar 28 17:34:29 UTC 2018 x86_64 GNU/Linux NetworkManager -V 1.10.6-3, Arch Linux
If you need any other info I'll be happy to give it.