Hm… I’ll go try it with the model you need, in the meantime, you test the model in a separate map, if you haven’t already.
Edit:
It’s working fine for me
Verify that you have all the files and that it’s not just the map.
Files I’ve copied over:
"cstrike\materials\models\props_blackmesa\light_sleek02_off.vmt"
"cstrike\materials\models\props_blackmesa\light_sleek02_off.vtf"
"cstrike\materials\models\props_blackmesa\light_sleek02_on.vmt"
"cstrike\materials\models\props_blackmesa\light_sleek02_on.vtf"
"cstrike\models\props_blackmesa\light_sleek02.dx80.vtx"
"cstrike\models\props_blackmesa\light_sleek02.dx90.vtx"
"cstrike\models\props_blackmesa\light_sleek02.mdl"
"cstrike\models\props_blackmesa\light_sleek02.phy"
"cstrike\models\props_blackmesa\light_sleek02.sw.vtx"
"cstrike\models\props_blackmesa\light_sleek02.vvd"