Good luck with this. Support told me to leave guild. I told them it's not working. They closed the ticket.
Hope they wake up and fall over a bag of lego bricks.
*** I created a new character and tested this myself June 3 and 4 2020.
I joined a guild in the Nederlands merchant alliance when I was between #46 and #68.
My alts experience plus the reports from this thread are combined for this synopsis:
The Beginner story line quests will disappear from your voyage log and side screens if you join a guild before you do/ complete up to #46. "Merchant Alliance's Call" .
If you join a guild After # 46 you will be OK the quest line DOES NOT break.
THE LONDON TRIPOLI BUG of # 71 and #72 when you did tripoli first - USE TO break.
I just did the quests, purposely did Tripoli first and was able to continue to London and then Santa Maria with NO problems!!!!
If you encounter the break at #45-46 problem, support tells you to quit your guild, HOWEVER this is NOT a working fix.
Even though your merchant alliance will show colored green in your Interaction (Ctrl+x) > Merchant Alliance tab >> see tabs of all 5 alliances (your chosen alliance is green lettered)
After you quit and wait 3 days, your quests are still missing.
So there is NO FIX for this bug - except to make a new character!
June 4, 2020
FOR REFERENCE ONLY - I did not have the quest line break
this is the location of the green lettering that tells you what Merchant alliance you are in.
BUG REPORTED TO SUPPORT JUNE 4, 2020
referencing this thread