That all sounds very strange, I've used Tuffsaw blades for a number of years though I don't buy many as they last a long time for my purposes and never had an issue of any kind. Have always found them to be very reliable and sharp.
The only time I get significant drift from a blade is after it's been used for cutting a number of tight curves but then I put those aside for specifically those jobs, I wonder if you've twisted yours while trying to handle that long timber though unlikely.
It would normally go through pine like a hot knife through butter so clearly something is wrong. Stupid question but you do have the blade teeth cutting downwards don't you? It's very easy to reverse the blade when uncoiling it and wouldn't be the first time. I've done it myself when not concentrating though noticed straight away.
It looks as if you bought more than one blade so what I'd do is swap to another blade and check it out after first carefully going through the saw settings again. It it's the same it's the saw, if it works then try the suspect blade again carefully adjusting settings and you'll know.
After doing this if you still think the blade is faulty ring Tuffsaws who will always help if they can.
I hadn't realised two whole years had gone by!
I think most people can relate to that. :lol: