I feel your frustration. I received my Quantum 2626 just a few days ago and was very upset that there was a lot of static noise.
First I will explain what I tried as these are probably good to do regardless of the real solution (which I will describe).
1. Eliminate ground loops. If you are unfamiliar with this then in simple terms it means plugging every piece of equipment being used into a single outlet or power strip. If for example you have your computer plugged into one wall outlet and your audio interface into another and amp into another, there is potential for a ground look (a slight difference in voltage between the sockets) and this can cause static. I tried this first and although it did not solve the problem it is good to do regardless.
2. Use a power conditioner. After getting more frustrated, I tried using a 300 dollar Monster power conditioner that I happened to have new and never used. This also didn't solve the problem but it is a good idea to have some kind of line conditioner to reduce noise and protect equipment.
After hours of frustration, and aa feeling that I had lost a good deal of money on my purchase, I found a setting in the Universal Control software that comes with the device. On the main page click settings and then choose options. There is a checkbox for "Enable optimized PreSonus power plan for Thunderbolt audio streaming". As soon as I tried this option the static disappeared.
In general the Presonus documentation for this product, Studio One 5 etc. is very poorly written and missing a lot of information. There wasn't any documentation I could find on this UC magic check box and I wasted hours upon hours trying to resolve the issue. I still don't really know what the checkbox does but it works and I can still keep my buffer size at 16 the minimum. I have a superfast and super expensive (3K) laptop with 3.5 TB of SSD, Thunderbolt 3 and a super fast multi-core processor and was really disappointed to be getting noise.
Presonus, first impressions count and yours was not a good one with this product. There are other manufacturers in case you weren't aware.
Hope this helps.