Multi Select attribute not updating

[Zarina2222]

Preconditions

1. Magento CE 2.1.2
2. Apache/2.4.18 (Ubuntu) PHP/7.0.8-0ubuntu0.16.04.3 MySQL/5.7.13-0ubuntu0.16.04.2

Steps to reproduce

1. I have multiselect attribute display_connectors
   
2. I have product TF-AEC-6635-A2M-1210 with this attribute and DP selected
   
3. Then I try to add VGA and HDMI options using Catalog product edit page
   
   or import csv-file
   sku,additional_attributes
TF-AEC-6635-A2M-1210,"display_connectors=DP,DVI,VGA"

Expected result

1. Product's display_connectors attributes should have DP, VGA and HDMI options selected

Actual result

1. Nothing happens, DP stays selected and also if I try remove DP it still stays there. This happens with all multiselect attributes. First time when product not yet have that attribute, I can normally select or import options I want, but if I try remove or add options later nothing happens.

[daniel-ifrim]

@Juigeli I have same problem in Magento CE 2.1.6.
This happens to me if I have 1 configurable product from other attribute set that does not have this attribute in it. It happens only for multiselect. I've tested it on CE 2.1.6 with sample data too.
@Juigeli Do you have a configurable product in related, cross or up-sell products like my case ?

[RomanKrut]

@Juigeli Unfortunately, I could not reproduce the issue as you described it. Maybe your issue was fixed, can you please recheck it on the latest version of Magento 2 ?

[Zarina2222]

I'm updating to Magento 2.1.7 on this week, maybe tomorrow. I can check the issue after that, hopefully updating fixes the issue.

[RomanKrut]

@Juigeli Tell us if this issue is still actual, or we can close it.

[veloraven]

According to contributor guide, tickets without response for two weeks should be closed.
If this issue still reproducible please feel free to create the new one: format new issue according to the Issue reporting guidelines: with steps to reproduce, actual result and expected result and specify Magento version.