Would love to see a vid from the side if you can. The side is the most useful angle for me to start making any recommendations if needed. Others may have a different suggestion.
Based on what you said, it seems to me that you just had bad timing - probably because in your mind, the amount of weight attempted was going to need some extra umph, getting you out of position and eventually off balance.
One of the potential issues I see with the 'grab and blast' (commonly referred to as the 'grip and rip' but I made this one up bec it sounds cooler) is that there's higher propensity for inefficiencies. I have a friend who's very strong with this method and he creates a ton of speed off the floor, but IMO, his technique and execution tends to suffer as a consequence. I feel he would be stronger and have a higher tendency to stay healthy if he would back off and focus on more deliberate timing from at least a semi-set position rather than just trying to mindlessly rip the weight off the floor.
The good aspect about the 'grab and blast' is that if you can dial in your timing - no matter what weight is on the bar- you're going to be a fast mofo off the floor.
You'll have to decide which approach you prefer and perfect it.
It takes practice to get the grip and rip down. My boy Ecks from another forum does the whole setup and grab the bar and adjust thing and missed his 2nd pull attempt in comp. we talked him into grip and rip before the 3rd attempt bc he's such an explosive lifter. 3rd attempt comes up and he nails the same weight he missed previously with great speed.