Why is it that the old node that I use get me disconnected when I connect to a game? I always use before but now it’s as if it turned bad. It used to be good even now the ping is good but when I logged in the game it disconnects.

Which mudfish node did you use? Did you try to change Connection Protocols to TCP based and test?
I am playing Ragnarok Online Philippines. My best node most of the time that I used before is the PH Asia-Philippines(ETPI) and SG Asia-Singapore(Aliyun) . After a few months it started to get bad. It used to be decent.
Now when I use my favorite node PH Asia-Philippines(ETPI). I can connect but very seldom and time based. I get disconnected, my character and others not moving and got stuck. But is playable sometimes when it is at the very night/morning like 12PM-7AM GMT. My second favorite SG Asia-Singapore(Aliyun) is now bad. Has bad delay.
I now am using new nodes but they have delay unlike my old ones that were decent before. I can still connect with PH Asia-Philippines(ETPI). I can connect in the log in screen which is still fast but when entering the game it fails or the screen is not loading anything, just my character getting stuck there.The only problem is when I enter the game.
Now I tried what you said testing the TCP. Yes I can connect now with PH Asia-Philippines(ETPI) with no disconnect but when entering the game it is pretty much just as fast as the other nodes I use in UDP which is delayed so it’s pretty much the same.
Is there a way I can get my old node PH Asia-Philippines(ETPI) or even SG Asia-Singapore(Aliyun)(which is now super delay unlike before) to get back to where it was not that much delay like before or even if it’s not these nodes anymore as long as I get another decent one.
I am using different nodes now but they aren’t that good unlike the old ones.
Umm… Please check MUDEC_00262 error link and try to change MTU to smaller one if it works with TCP based properly. So it looks UDP connection protocol is best if it works properly.