Do not teach your child to flap around with flotation devices. Teach your child water safety and how to rescue themselves first, then learn how to swim.
Edit; stop "teaching" your child to swim and take them to a swim school.where you like the look of the way lessons are tauggt and the teachers. Interaction with the children.
Remember as much as you and I love the water,it can be completely terrifying to a grom,moreso as they get older.
I could go to most swims schools and take away all of their "flotation devices" and sadly most kids would become scared or sink. So many good kickers out there but groms that cannot save themselves. Sorry to sound harsh,but deluded parents trying to teach themselves is just as dangerous,or in reality will take longer to teach the child to swim,as once they have been spooked it very difficult to win their trust back.
So.find a good school with good teachers. Or use a bit of common sense.
Here is a tip to see how child reacts to water and where could start teaching from.
Will the child put their face in the water?
Will the child open their eyes underwater?
Will the child then go underwater and get a toy of the bottom?
Obviously all without floaties.
Also never make a child do something that are afraidd of no matter how much you think they should not be
Swimming is fun,being taught to save yourself is life changing