Change of status from L1B to H4, Expired Approval notice, I-94 valid

Currently am in working in L1B. My Visa got expired and I 94 is valid.

My husband is working in H1B. Is it possible to change my status to H4(my Visa expired)
If yes, when should I stop working?

Pls share your thoughts

You should stop working immediately, if you do not have valid approval notice. Just having I-94 validity does not give you legal status. You need maintain status and have proper approval notice.
Yes, you can apply for COS to H4. Discuss with your L1 company and plan for extension or change to H4 immediately, if you do not plan to get L1 extended.

It’s legal to work with valid I-94.

The question which I have is, is it possible to convert from l1b to h4 only with valid I 94 and Visa expired?

I-94 is only entry exit document, what determines your work authorization is your Approval notice attached to it. Check with an attorney… If I-94 valid, you maybe able to…again, all boils down to proper authorization tied to your I-94. Check with attorney.