Hello - you are saying you are getting a "stuck mash"? Your ratio of strike water to mash volume is good BUT you probably didn't account for the volume of water underneath the false bottom.
Also, it is possible you simply didn't let the mash set for a few minutes before starting recirculation. Letting the mash set allows the grain to expand into a looser bed and settle in.
1) I let the mash set up for a good 5-15 minutes before starting to recirculate. Even then I manually (very very slowly - like a quart a minute) vorlauf a few times to make sure everything is ok.
2) When you start the recirculation you need to close off the valve at the END of the recirculation system to limit the recirculation to just a trickle... then every couple of minutes open it up so it is running at whatever speed you want to run it at.