Hello. You can telnet to IP:PORT and WINMTR to IP when it happening ( contact me via Livechat, bottom right, for IP:PORT ).
"-Network is fine otherwise, other websites, games, etc all are 100% fine." - please, please, please EVERYONE stop using this as your argument. It's stupid. Using this argument you are saying that this 2 roads are same https://prnt.sc/tr9pql
2nd argument I hate is "it's not my provider, because other games not lagging". This is example: https://prnt.sc/tr9snd ( small blue marks is data centers which your packets just passing ). We can't control what data centers your provider choosing between you and our server. And if there will be any issue in any data center between you and us - you will have lags. Nothing we can do about it, but your provider can change your packets path ( not instantly, but possible ). Before we get your packet - it's your provider responsibility to not lose it.