That could definitely explain the nute burn. You will come up with a watering/feeding schedule that works for you.. It takes practice, and a ppm meter, lol.. In soil, the most common watering/feeding schedule is feed-water-water-feed.. On the 2nd water only day you can check the ppm of the run off.. If it's lower than what the feed mix was, the plant is feeding fine. It's using the nutrients that are available. The issue with back to back feedings in soil, or using nutes every time, is that you are always adding more to the soil and not giving the plant time to use what was already there. That's how an excess can happen...
How often you feed is relevant to how much you feed.. Lighter feeds can be given more often, heavier feeds may need 3 water only days in between.. That's where knowing your feed ppm comes into play.. If your mix is 1000 ppms, then you would use water only until the run off was like 4-500.. Then feed again.. If your mix is 300ppms, you can probably feed every other day.
But at this point you just want to stop the issue from spreading. Autos have zero recovery time so you wanna check the basics (like ppms of your feeds, your plain water, and of some run off) and try to get her to harvest without the issue getting worse.
The pic you posted from fast buds does not match what you say you've been feeding. Im kind of confused now.. Weeks 2-4 on bio bizz grow feed chart says to use 2ml per liter.. That's 8ml per gallon.. The fast buds chart you posted says to use 1/8th nute ratio week 2.. That would be 1ml of bio grow per gallon.. You say you started week 2 at 1ml per liter, or 4ml per gallon.. Either way.. The only way to know what's best at this point is to check the ppms..