Hello.

So I'm getting really desperate, don't know what to do.
Been searching for a fix for past 2 days.

So, some users on my server have stable 0% packet loss, some of them have 15-20%.
I first thought it was a firewall problem, (Using Debian 9) i disabled ufw, problem's still there.
Asked my VPS Hosting to change IP of my server, they did.
After that, one client that had 15-20% packet loss, has 0%, but some clients still have 15-20%.
I have no idea what to do.

Here's WINMtr from one user -> server:
|------------------------------------------------------------------------------------------|
| WinMTR statistics |
| Host - % | Sent | Recv | Best | Avrg | Wrst | Last |
|------------------------------------------------|------|------|------|------|------|------|
| 192.168.1.1 - 0 | 640 | 640 | 0 | 0 | 5 | 0 |
| 1-48-40-46.dynamic.stcable.net - 1 | 636 | 635 | 6 | 13 | 810 | 9 |
| 91.102.226.254 - 0 | 640 | 640 | 6 | 11 | 86 | 9 |
| 91.102.227.33 - 0 | 640 | 640 | 9 | 16 | 118 | 11 |
| ae3.RT.TNR.BEG.RS.retn.net - 0 | 640 | 640 | 7 | 11 | 33 | 10 |
| ae5-10.RT.TC2.AMS.NL.retn.net - 0 | 640 | 640 | 40 | 44 | 81 | 40 |
| 80.249.210.43 - 0 | 640 | 640 | 42 | 45 | 58 | 43 |
| ams-eq6-01c.voxility.net - 0 | 640 | 640 | 39 | 45 | 247 | 42 |
| fra-in8-01c.voxility.net - 0 | 640 | 640 | 44 | 51 | 254 | 48 |
| ddos.protection.interwerk.de - 0 | 640 | 640 | 44 | 51 | 92 | 46 |
| 185.223.28.137 - 15 | 409 | 351 | 44 | 48 | 75 | 47 |
|________________________________________________| ______|______|______|______|______|______|

Here's MTR from server -> client that has 15-20% packet loss:
1. 31.214.141.1 0.0% 234 0.2 5.1 0.2 50.7 9.2
2. decix.net.telekom.hu 0.0% 233 23.5 23.9 23.3 32.0 1.0
3. 81.183.3.63 0.0% 233 23.3 23.4 23.1 26.8 0.5
4. 81.183.3.141 0.0% 233 23.4 23.6 23.4 27.0 0.5
5. 81.183.2.95 0.0% 233 35.5 34.0 32.7 38.8 0.8
6. 91.102.227.26 0.4% 233 42.5 58.4 40.5 3605. 234.0
7. 91.102.226.226 0.0% 233 36.1 39.2 35.9 77.4 6.7
8. 59-52-40-46.dynamic.stcable.net 13.7% 233 50.5 49.5 45.6 78.3 4.7