Here is the simplest example:

2022-01-01 test
  assets:1  1 UNIT @ 1 USD
  assets:2
2022-01-02 test
  assets:1  -1 UNIT
  assets:3

The output:
For both hledger-web -E and hledger-web, the output is the same:

Expected output:
Just like the above picture, but assets:1 account should not appear at all in hledger-web -E, as it is now empty.

Related explorations

I've tested it in hledger, which is working correctly.
Note in hledger, -E shows 0 account, but in hledger-web, -E hides 0 accounts.

hledger bal
              -1 USD  assets:2
              1 UNIT  assets:3
--------------------
              1 UNIT
              -1 USD

hledger bal -E
                   0  assets:1
              -1 USD  assets:2
              1 UNIT  assets:3
--------------------
              1 UNIT
              -1 USD

The version: hledger-web 1.32.1, mac-aarch64