I performed the same steps and ran into the same problem. I found that the problem was resolved by removing the ~/.pgadmin directory (created during installation) and then re-running "python pgAdmin4.py"
It's kind of a shame that there is no good solution to this. I found that adding EXPLAIN ANALYZE to the beginning of my query will display results. Some documentation can be found here.
Example:
EXPLAIN ANALYZE
select * from schema.my_table limit 1000
Best Answer
Try File - Preferences - Dashboard within PGAdmin. See if toggling those options will bring it back.
If not, then providing you do not have any customised layout, try File - Reset Layout.