Please, you don't have anything to worry about it. A lot of parents think it's "normal" for a baby to start sleeping through from a very very young age but it's actually quite normal for babies to only start sleeping through from anything between 2 - 5 yrs of age.
Babies still have a lot of needs to be meet during the night. The get hungry, thirsty or they might be hot or cold, teething, ear ache, other illness etc
They grow through a lot of development milestones, from sitting alone, to crawling, to walking etc and that can also affect their sleep.
There are 10 wonder weeks that happen before the age of 2. You can google wonder weeks to get an idea of what I'm talking about. Then there are also growth spurts where the need to feed increases as well and they wake up more often.
By the sounds of it, your little one is actually sleeping quite well.
If there is no medical issue, don't be concerned. There is a lot happening in that little body!
Also don't think you have to be concerned but I for one love my sleep and when baby sleep all of us are just functioning better.
We did the sleep sense programme with GoodNight Baby.
It is a very gentle approach to help and learn your baby to fall asleep on his own when he wakes up and not to rely on sleep props, for example the dummy.
It has changed our lives and my son, now 2.5 is sleeping like a log almost every night.
They do go through growth spurts and emotional development which do affect their sleep but if they have the know how they transition back to good sleep very fast.
Give it a go, what do you have to loose?
Good luck and keep us updated!