[Bug Report] EL-Select Options Not Showing

### Element UI version
2.15.1

### OS/Browsers version
MAC

### Vue version
2.6.12

### Reproduction Link
https://jsfiddle.net/

### Steps to reproduce
https://jsfiddle.net/mmx38qxw/

### What is Expected?
EL Select Options need to load/display

### What is actually happening?
When i Load Data from DB for EL Select its not working, if i manually enter value in frontend then its work

https://i.stack.imgur.com/1enwo.png

https://i.stack.imgur.com/AYnG0.png

https://i.stack.imgur.com/wpFnI.png