Did you mark them as equipped and attuned?

Shrek mittens

Are unarmed strike attack from these considered magical?

I find it bizarre that items that replace potentially several ASI's fall under uncommon. This seems like a really powerful thing.

This is probably to counter-balance the frustration of not being able to equip some items due to a lack of ability score, or not being able to multiclass for the same reason.

Check to see if you attuned them on your online character sheet.

These on a fighter. 

Other than the possible edge case of a fight vs a beholder, can you think of reasons to NOT rebuild and dump strength to a10?   9?  Even an 8?

According to rules as written, can items like this be used to satisfy multi-classing requirements?  The reason I'm asking is because my level 8 Twilight Stout Halfling Cleric usually has a STR of 8.  But now he's got these gauntlets, making his STR 19.  I've been considering multiclassing with this character, and now when looking ahead at what I'm going to do at level 9, D&D Beyond is telling me I can now multiclass into Barbarian and Fighter.  I was not being given those multi-class options before I attuned to the gauntlets.  So again, my question is, can items like this be used to satisfy multi-classing requirements?  According to RAW?  What say you, D&D Beyond Community???  ;)

We are doing a short campaign. Starting level 11 he is allowing 2 uncommon magic items as part of our starting inventory. I took gauntlets of ogre power and glaive of warning.
 I’m a VH fighter 8/ barbarian 3 w/ PAM/Sentinel

using point buy I have a 19 Str 16 Dex and  20 con 12 int 12 wis 9 cha.  when I go barb 4 I’ll take a feat(either tough/GWM)

plus we will have 6500 Gold to buy whatever.

any ideas? 

Quote from BDBazinski >>

🎶Somewhere ogre the rainbow...🎶

 Stranger from the far past, I salute you for this wonderful dad joke.

Quote from ShazMyBot >>

“It's all ogre now”

gets punch in half by ogre

I think it may have raise your Strength score without these on, but because you have them on it is 19. when you take them off and unattune, your strength will be improved due to the ASI.

Can a sorcerer use this or is it considered armor?

It's classified as a "wondrous Item" not "Armor (plate), very rare". According to that, your sorcerer can attune to this item.

Heck yeah!

Nope

Fishing 

Then she slapped me in the face!
Now I'm a believer! 

You Ogre believe I started to have faith when 
I got back handed by some one wearing gloves like these!

very good