You don’t have a lot of cover, which makes a lot of fish etc. more shy. Some easy floaters like red roots would probably help to make then feel more secure without needing to drastically adjust your scape
So my boas do that aswell. I have 9 in a 10 but barely see em I would say you can add some food in the front. Also GET 2 MORE PYGMYS THEY NEED 6 OR MORE
Normal with big open areas and few small creatures. The more you have, the braver they’ll get.
Give the shrimp some time to breed (they do so fairly explosively) and maybe grab a few more pygmy Cory’s. You want at LEAST 6, ideally 8-10. They’ll hide less with larger numbers.
octaneveins 
You don’t have a lot of cover, which makes a lot of fish etc. more shy. Some easy floaters like red roots would probably help to make then feel more secure without needing to drastically adjust your scape
So my boas do that aswell. I have 9 in a 10 but barely see em I would say you can add some food in the front. Also GET 2 MORE PYGMYS THEY NEED 6 OR MORE
Normal with big open areas and few small creatures. The more you have, the braver they’ll get.
Give the shrimp some time to breed (they do so fairly explosively) and maybe grab a few more pygmy Cory’s. You want at LEAST 6, ideally 8-10. They’ll hide less with larger numbers.
check your filter they might be in there