This problem occurred around June but there was a fix for it which was posted on the 11th of June. Refer to the points 2 & 3 below (taken from discord). I think if you guys experienced the Jean missing issue in June and did not auto-complete by the 15th, the option to autocomplete has been removed. Not sure what it means by manually completing them; but maybe you'd have to redo the morass questline?
(I had this issue previously and manage to fix it via the autocomplete method.)
Spyro 06/11/2020
This notification serves to address the remaining issues incurred on June 6, 2020: @everyone
[1] Accounts that are logged in from now until June 15, 2020 (regardless if the account was affected by the server issue on June 6) can claim a free 30-day Additional Pendant Slot Coupon via the Universal NPC option and selecting 'Autocomplete Reverted Quests' then 'Claim 2nd Pendant Slot Coupon'. Players can only claim the complimentary slot coupon once per account, where the coupon will not be tradeable and the option will be removed once it is claimed. Please be advised that upon claiming, the coupon will last for 30 days and cannot be used if an Additional Pendant Slot is already active.
[2] Characters that were unable to find the Jean NPC after auto-completing the Arcane River quests can now use the '5th Job & Arcane River Quests' option again to resolve this issue and where the NPC should return for the completion of Morass Daily Quests.
[3] Please be advised that all players that were affected by the server issue on June 6, 2020 are to utilize the auto-complete options via the Universal NPC by June 15, 2020 where it will be removed from the Universal NPC. Any player that is affected by the server issue and has not reinstated any of the affected quest progress after June 15 will have to manually complete them.