[Bug]: After sending a transaction on custom networks, the balance disappears if the network manager selection is different than the sending network

### Describe the bug

If network manager selection is a single network and a transaction is sent on a custom network (or Sepolia test network), then the balance on the custom network disappears.
Closing and re-opening MetaMask solves the issue.

### Expected behavior

No balance disappear

### Screenshots/Recordings

https://github.com/user-attachments/assets/b8e729a6-ef4a-4bb6-9ca7-af2b57cda1fd

### Steps to reproduce

1. Add custom network or Sepolia test network
2. Switch to BNB chain in Network Manager (or any single popular network)
3. Send transaction on custom network or Sepolia test network
4. Switch to the custom network
5. Notice the balance disappeared
6. Close and reopen MetaMask
7. Notice the balance is displayed again

### Error messages or log output

```shell

```

### Where was this bug found?

Internal release testing

### Version

13.37.0

### Build type

_No response_

### Browser

Chrome

### Operating system

MacOS

### Hardware wallet

_No response_

### Additional context

_No response_

### Severity

_No response_

Start by reproducing the issue with a custom network or Sepolia, a single BNB network selection, and a transaction as described in the issue. Trace the balance state when switching back to the sending network; done means the balance remains visible without closing and reopening MetaMask.

Written by the indexing model from the issue text.