Mono record sounds like stereo

So I have been playing stereo records for 40 years.  I’ve recently acquired some Verve Japanese reissues. Listening to Metronome All stars tonight and there is clearly separation. I hear horns predominantly on the left and xylophone and drums on the right.  This is on an Ortofon SPU synergy stereo cartridge. Is this normal ?  I’m sorry.  I’m new to Mono.  I bought about 50 verve and Blue notes last week and got some monos on accident.  My system is balanced and the room has extensive treatment so I’m lost !