I have purchased Player's Handbook, Tasha's Cauldron of Everything, Dungeon Master's Guide, Explorer's Guide to Wildemount, Eberron: Rising from the Last War, Volo's Guide to Monsters, Xanathar's Guide to Everything and I opened the content sharing for my campaign. My players can choose all races that I own from the books but I somehow can't see some of the races (eg. vedalken, tiefling variants) How can I fix this? I paid for those and I want to play with those.

Make sure that you turn on any special content types that the race you're after requires like Critical Role Content and so on if it applies. If it's not that - check your entitlements are in sync here: https://www.dndbeyond.com/account/marketplace

How recently did you buy them? Same day? Sometimes it can take a bit for everything to come online, especially if you bought them all at once. Otherwise Member’s got you set right. (As always.)

I've been buying them when I see there are sales. I bought them separately.

every content is open. My players can open every character and I cannot even tho I'm the one who paid for it. Although I recently found out when I make a character in a campaign that's ok but outside of the campaign, not ok. weird bug

Submit a ticket, if you haven't already.

Quote from Lorenzo422 >>

I have purchased Player's Handbook, Tasha's Cauldron of Everything, Dungeon Master's Guide, Explorer's Guide to Wildemount, Eberron: Rising from the Last War, Volo's Guide to Monsters, Xanathar's Guide to Everything and I opened the content sharing for my campaign. My players can choose all races that I own from the books but I somehow can't see some of the races (eg. vedalken, tiefling variants) How can I fix this? I paid for those and I want to play with those.

I'm finding it weird that people are overlooking the super basic issue here.

The races you want, are not in the things you purchased. This is why you don't have them. Go buy them from the sourcebooks:

Vedalken: Guildmaster's Guide to Ravnica
Tiefling Variants: Mordenkainen's Tome of Foes

But how come the players without any books can pick up those races? I'm the only one with the books. But I figured it out

Most likely one of your other players may own those races or sourcebooks, and their content is also shared with the campaign, even if they don't have Master Tier subscriptions. But if you're creating NPCs for encounters, or PCs elsewhere than within the campaign, you don't have access to that shared content yourself.