Bad internet quality, Don't know what else to do!

Hi,

I've been a videotron internet user for the last 4 years and was overall happy with my internet. I work in visual effects and need high frame rate for my work. we use pcoip on a thin client with HP anywhere client to connect to a linux machine.

Everything was good since about a month ago, where the quality of internet went down. it got slow and laggy. I contacted videotron support and was told my line was okay. After insisting more, they sent a technician and he changed our helix modem. Also I upgraded our package to 1 Gbps.

However the problem is still there. I'm using a CAT8 Ethernet cable from helix to my dell machine. And according to the technician, the cables outside of our house are good. 

my Pcoip has a connection health monitor. It shows:
Connection=Poor
Packet Loss = 0.7%
Latency = 77 ms

When i do a speed tests, i get different results depending on which test i do. Using the page we use at work:
Download = 70.6 Mbps
Upload = 49.1 Mbps
Ping = 74.1 ms
Jitter = 3.60 ms

But using Ookla speed test:
Download = 390 Mbps
Upload = 56 Mbps
Ping = 15 ms

Using Librespeed:
Download = 202 Mbps
Upload = 61 Mbps
Ping = 19 ms
Jitter = 2.21 ms

I contacted videotron again, and they said there's nothing more they can do and it is what it is. We live in Saint-Hubert in south shore of Montreal. Unfortunately there aren't many other internet options available here, there is only Bell, but the maximum speed they offer here is 100 Mbps which is too slow for me.

I don't know what else i can do. I'd really appreciate any help i can get. Thank you!