Two issues, which may be related. After creating a 2024 version of my College of Lore bard (lvl 5 Bard, lvl 2 Warlock), I noticed that the short description for Jack of all Trades is reading incorrectly. Reading:

You can add half your Proficiency Bonus (1) ability checks you make that uses a skill proficiency you lack and that doesn’t otherwise use your Proficiency Bonus.

I assume this should read "You can add half your Proficiency Bonus (1) to ability checks you make that uses a skill proficiency you lack and that doesn’t otherwise use your Proficiency Bonus."

The other thing I noticed was that my initiative bonus is now one less than the 2014 version (+1 now vs +2 with 2014). My dexterity modifier is +1 so best I can assume the Jack of all Trades feature is not applying to my initiative. Based on the new reading I am guessing this is on purpose, because there is no Initiative skill, but wasn't sure.

I just noticed the same problem. Old bard had a +5, new bard has a +3

I am guessing the change in Initiative is that Jack of all Trades no longer applies as there is no Initiative proficiency to lack.

You can add half your Proficiency Bonus (round down) to any ability check you make that uses a skill proficiency you lack and that doesn’t otherwise use your Proficiency Bonus.

The 2014 Jack of all Trades didn't refer to skill proficiency, it referenced all ability checks.

Starting at 2nd level, you can add half your proficiency bonus, rounded down, to any ability check you make that doesn’t already include your proficiency bonus.

My guess is that applying to Initiative was just a player-friendly side effect of the wording, and with the revamp to skills and tools and other proficiencies they probably wanted to make things simpler for DMs and players.