Vomiting after each meal gastric sleeve surgery - Should I be concerned and contact my GP or is it a normal reaction?

You should definitely contact your GP or bariatric surgeon as soon as possible. Frequent vomiting and dumping syndrome after nearly every meal, especially this far out from surgery, is not normal and could indicate an underlying issue. One possibility is a stricture, which is a narrowing of the stomach opening that can cause food to get stuck, leading to vomiting. Another potential cause is gastroparesis, a condition where the stomach empties more slowly than normal. Severe dumping syndrome could also be a factor, though it is more common after gastric bypass than after a sleeve. Additionally, you might be experiencing food intolerance or reflux, both of which can trigger nausea and vomiting.
Losing more weight than intended and struggling to maintain your weight suggests that your body may not be absorbing nutrients properly, which could lead to malnutrition or dehydration. Your doctor can run tests, such as an endoscopy or imaging, to check for complications and help you manage your symptoms. Until then, try to stay hydrated and focus on softer, well-tolerated foods.

Some people experience nausea after surgery, but if it lingers past the first few days, then you really need to see your surgeon so he can do a follow.  You should not be experiencing vomiting daily, or even regularly after your sleeve surgery.  Make sure you are really chewing your food thoroughly, don't eat and drink at the same time, stay away from foods that can swell like bread, rice, pasta, stick with protein rich foods.  Your doctor may want to put you back on liquids for a short time to see if that resolves the issue, otherwise you may need an upper GI to determine the issue.

Hello, The best recommendation is to contact the doctor who perform the procedure, it's for your best if the doctor check on you to prescribe medication.
In addition to other criteria such as medical indications and safety, behavioral health assessments, and so forth I recommend that you go to your certified doctor so he can guide you and do the check up necessary to assist you.
My  Best Wishes