Bug reports are filed in game are not dealt with via Support. Please do not clog up the support system with bug reports. Support do not pass on bug reports. A bug report goes to the right people and but you wont get a response.
The Devs are aware of the issue:
https://eu.battle.net/support/en/article/328860
It is a known bug and if the fix has not worked I’d file another report.
There is a link in the support forum to the known bugs list, the last update looks to have been done back in December.
The work around for the climbing quest is to shard hop until you find a working one or use the group finder to see if someone has listed a shard where it isn’t broken.