I have a rather strange (probably) connection related issue while playing online games that Iíd like to get help with. Iím basically experiencing a very noticeable (by the feel of it up to several hundreds of ms) lag while playing time-sensitive games - latest iterations of Call of Duty and Battlefield for example. The games have an unresponsive and off feel to them, enemy players see me way earlier on their screens than I see them and shots have a hard time registering Ė it is like playing half a second behind the server constantly. The feel of the game is rather similar to having major latency, packet loss and even framerate issues.

Now the real problem is, that none of this is clearly indicated by the game or any monitoring software Iíve tried so far. 99% of the time the games show a stable 40-50 ms ping and 0% packet loss with a rather high FPS value, regardless of whether I play in the middle of the night or at peak hours. Iíve been using PingPlotter for the past few days to try and identify any patterns that would explain what I experience ingame.
I used Call of Duty as the testgame, I played it in the morning and in the evening (at peak hours) for two consecutive days, constantly pinging all European CoD servers with UDP packets in the meantime. Despite having dedicated servers, many matches in CoD are still peer-to-peer, but I figured that pinging the servers would still give a general idea of whatís going on. I used Dumaosí Ping Heatmap to gather server IPs. Matches were played on a high-end gaming PC maxed out for the lowest possible input lag with a fresh Windows 10 install.

I used two different ISP and router combinations on the two days with the test PC being the only device connected to them (via ethernet cable):
Day1: Gbit fiber with the ISP router in bridge + my own Netduma R2 router (port-forwarded)
Day2: Gbit cable with the ISPís own router (on stock settings)

Iíll include the PingPlotter results (hope itís not too much):

Server IP:
Day1 morning https://share.pingplotter.com/4gsFQf9MWuR
Day1 evening https://share.pingplotter.com/Udst5JVA6Kj
Day2 morning https://share.pingplotter.com/EqTeM3fn3S1
Day2 evening https://share.pingplotter.com/2xHooVXQxey

Server IP:
Day1 morning https://share.pingplotter.com/9sBzoh8gngW
Day1 evening https://share.pingplotter.com/HaDPU95wxxY
Day2 morning https://share.pingplotter.com/iFzUzHkuPH2
Day2 evening https://share.pingplotter.com/TVpZYcdxusq

Server IP:
Day1 morning https://share.pingplotter.com/FvL8xYA8rJY
Day1 evening https://share.pingplotter.com/8tXWXMrjHqH
Day2 morning https://share.pingplotter.com/bDePwv89tXR
Day2 evening https://share.pingplotter.com/CEpdjbj4f9S

Server IP:
Day1 morning https://share.pingplotter.com/JSGfwDHu2A
Day1 evening https://share.pingplotter.com/TyKsTgWEasq
Day2 morning https://share.pingplotter.com/PHvDsGEaPya
Day2 evening https://share.pingplotter.com/U5KsZJRL2w6

Server IP:
Day1 morning https://share.pingplotter.com/cABoJLdGQcN
Day1 evening https://share.pingplotter.com/aZve6cYu1p9
Day2 morning https://share.pingplotter.com/DwsPSxXBtjo
Day2 evening https://share.pingplotter.com/BPo3gtVS1Bu

Server IP:
Day1 morning https://share.pingplotter.com/ivvzyjfV4Hx
Day1 evening https://share.pingplotter.com/CxHnS6ir86L
Day2 morning https://share.pingplotter.com/b8LpkFWGtkt
Day2 evening https://share.pingplotter.com/TnHRYNeKbPa

Server IP:
Day1 morning https://share.pingplotter.com/g3HUYxKYs2b
Day1 evening https://share.pingplotter.com/CHVg8SF3tsd
Day2 morning https://share.pingplotter.com/LHgfF4VBGw7
Day2 evening https://share.pingplotter.com/RHChTAGK1qi

While the data may show some differences depending on how and when it was captured, the feel of the game was EXACTLY the same in all scenarios, meaning it alternated between a bad experience and near unplayable among individual matches (even when PingPlotter showed the best results). I may not be an expert in evaluating PingPlotter data (hence the post), but I donít think that even the worst measurements match up with my experience ingame.
Iíve probably had this issue for several years now, but I hadnít been aware of (or irritated by) it until a few months ago when I started focusing again on fast-paced online games.

My primary questions are:

Does my data indicate some big problems Iím unaware of? Or should I make additonal tests with a different experimental design?
Also, is it possible to have connection issues without any monitoring software detecting anything?

Any help would be greatly appreciated.

Thanks in advance.