Is having a cyst like lump normal to have after chalazion surgery?

You need to get a second opinion.  What you are describing can be normal after chalazia surgery and may reflect a healing eyelid.  Or it may reflect an incompletely excised chalazia.  Generally, I do not recommend chalazia surgery unless the lesion has failed injection with the corticosteroid kenalog.  In 20 years of practice, I seldom find a chalazia that does not respond to a kenalog injection.  I suspect you may still benefit from that.

The small lump is most likely related to the healing after incision and drainage of the chalazion. This thickened area is likely to resolve spontaneously - but may take some time. Over the next few weeks, you should notice continued improvement. See you surgeon for follow up, so that he/she may advise you about your progress. Best wishes.

Absolutely normal!!! The surgery on the chalazion drains the more fluid part leaving behind the more solid "wall" of the "cyst".  Over months your body will dissolve the wall which is made up of scar tissue created by the inflammation.  What you are experiencing is to be expected and I hope you heal well.