Found out that above patch does retain previously selected values when editin...

Contribution Date
Technology
Drupal
Contribution Project
Improved Multi Select
Contribution Details

Found out that above patch does retain previously selected values when editing the entity with select multiple fields. Here's the new patch that works for me.

Contribution Author
Sushil Hanwate
Contribution Issue Link
Only one of the multiple selected options are saved after form submit.
Contribution Link
https://www.drupal.org/node/2850654#comment-11926348
Files count
1
Patches count
1