Sure, divorce case is different to if you were still married and travelling together. Even in good times, during ROC, CBP asked me how do I usually travel - solo or with my spouse. Mind you, my spouse entered the US a minute earlier on that trip 😃
You're still LPR and should be able to enter the US on valid stamp. Unless you have other issues in your immigration history, you should be able to travel.
You may be briefly placed in secondary upon reentry.
It's up to you, lawyer is being overly cautions, it's their job.