[Bug Report] el-popover shows two of popovers on specific condition

### Element UI version
2.15.6

### OS/Browsers version
macOS Ventura / Google Chrome 107.0.5304.121

### Vue version
2.6.10

### Reproduction Link
https://codesandbox.io/s/popover-double-rendering-etzxkg?from-embed=&file=/src/App.vue

### Steps to reproduce
1. Place el-popover inside el-table-column
2. Add ‘fixed’ property in el-table-column
3. Add ‘v-model’ or ‘value’ property in el-popover
4. Click the button in table
5. Narrow the width of browser for observing appearance of two popovers

### What is Expected?
Only one popover appears.

### What is actually happening?
Two of popovers appear.

At the first time, it seems only one popover appears because they are rendered in the same position. Overlapped popovers are separated then appeared to user, if the width of browser narrowed.