BB sleeve warped

Hi all, just for makes things clear, English is not my native language so bear with me if some parts result odd to read

I've built my bike some time ago without (or I simply don't remember) check properly some stuff

My bike shell is 68mm, at the time I was aware that for this kind of shell I should use an hollotech MTB BB

Or at least it was the cheapest compatible solution at the time

Little I know that I should have check at the time also the crank compatibility

I've a FSA gossamer, apparently a road crank set
The spindle length is 10.8mm

At this point makes sense why the spacer installation were odd, I've installed only a big spacer on drive side, the crank anyway never really gave me problems but it never rotated freely like sometimes I've saw online

Anyway, today, for the first time, I've decided to do a proper deep cleaning of my bike and I find out that the sleeve of the bottom bracket is warped on the drive side

I've tried to search replacement for sleeves online but I couldn't find much; I'm really tempted at this point to buy a road BB and call the day

I'm not really happy to waste stuff, because the BB have still life and all things aside are in good condition

I would like to have some opinions about the sleeve at this point

I think that is possible that it warped because I've installed wrong the bottom bracket the first time, but doesn't make sense in the long run because the crank itself always worked fine in the last 4 years ( no strange wabbling, sounds or resistance)

Just for future reference, what should I use exactly in the case of a hollotech MTB BB with a road crank set?

Online I found different opinions from that it doesn't really matter to just add 1 mm spacer per BB side
But also I found that in my case is suggested to use a road sleeve with MTB hollowtech BB

Also where should I find in UK the spacer? Does anyone know if the sleeves are sold separately? Because I've found 1(like only one in general ) road sleeve on eBay for 5 quid