Packet loss (fiber)

Yesterday, I "upgraded" to fiber, since then I've been experiencing packet loss, but it's very confusing, I really can't find out whether it's me or my ISP, I've seen so many conflicting situations that make me think it's me, but I'm pretty sure it isn't.

3 types of packet loss

1 - Basically sitting there doing nothing, bandwidth monitor open on my router and cmd pinging google.com, everything is running smoothly, but then shit hits the fan. CONSTANT dropped packets, usually coming in synchronized pairs, aka 2 packet drops out of every 6...

2 - This one is a bit more understandable, it's buffer bloat. When downloading, not necessarily even maxing my bandwidth, but just downloading at maybe 5-8 Mbps, I get dropped packets. <- This makes me think it's my ISP.

3 - cmd ping to one host dies (looks like dropped packs, but actually, the internet is fine because as soon as I restart the ping to that same location, it works. Virtual packet loss in this case? To fix this issue (or so I thought), I turned on Extend and Spoof TTL on my router. To no avail.

What I've already done:

- Ping from different devices to confirm results (both LAN and Wireless)
- Gone through 3 ethernet cables for modem > router connection.
- Tried several MTU/MRU values (this one seems to have helped at least a bit)
- Ran traceroute, can't put my finger on a specific hop being the issue.

Here are the Fiber optic statistics provided by my modem, do they look okay?

Transmitted power: 2.8 dBm
Received power: -11.12 dBm
Temperature: 57.93oC
Voltage: 3.29 V
Current: 10.39 mA

I don't want to jump to conclusions and blame my ISP, after all, it is fiber and the chances of it being the main issue are extremely slim, no?

Is there anything else I can do on my end? Any tests I can run?