I drew 2 shapes through Canvas (JS). The first disappeared, the second remained. Why is that?

Question

css

First I drew the first figure. Everything is correct and working. When I drew the second one, the first one disappeared. And even the second figure is drawn much lower than the first. How to fix? Help me please.
The whole code is too capacious, so I will write only the parameters that I mainly used:

context.beginPath();
context.moveTo();
context.quadraticCurveTo();
context.lineWidth = value;
context.strokeStyle = "color";
context.stroke();

Each figure began with

window.onload = function() {
  var canvas = document.getElementById("example");
  var context = canvas.getContext("2d");

PS There are no errors in the code. Another figure - another ID.

Answer 1

You do not need to start each figure with

var canvas = document.getElementById("example");
  var context = canvas.getContext("2d");

The context is enough to get 1 time