Telegram groups for new accounts

I just launched a brand new account and posted a high quality photo with some good hashtags. From the engagement groups I got maybe around 350 likes and currently I have about 375 and i think from another person's point of view this seems like it has been boosted with fake likes. I see people here growing their small accounts insanely quick... How? My hashtags were very closely related to my niche, but also I think that some are too big (500k + tags), so do you think it's a good idea to focus on the smaller hashtags at the moment 300k or below? I did 4 rounds with engagement groups from my bigger account and it got a boost for the first 40 minutes then completely died, so it seems like I am doing something wrong. Any tips are appreciated guys