The separate presentation of cash at bank and cash on hand on the Summary page ended several months ago. Cash and bank accounts were merged into a single Cash Accounts tab a month ago. See [16.5.6] Merged bank accounts into cash accounts tabs - #29 by AntonisV.
If you want to specifically create a category that summarizes only bank accounts, going back to the old way, you can do so with custom control accounts. Read the relevant Guides and search the forum on that topic for guidance.