First - no feeding at all. Its the feeding that give your NH3/NH4. Dose large amount of nitrification bacteria like nitrospira. If you go
to my 15 steps - you will have some other tips how to get bacteria into your aquarium.
But NO FEEDING till you read no or very low NH3/NH4. If you know your pH -
you can use this tool to calculate how much of free NH3 you have (NH3 is the toxic form) The picture shows the calculation I did on your measured level of 4 ppm total ammonia
You can see that you are near the limits for acute toxicity. Your notes show a pH of 8.1 - if that´s true - it is good in this situation. If your salinity is higher (it should be) the NH3 amount is lower.
But do not feed. The fish is probably stressed - you are in a situation - it is very difficult to give advises. Moving into new aquarium could be worse, changing water too (new mixed water is stressful) If they do not show any signs of problems - it can be better to let it works out. But you are the one that need to take the decision what to do.
BUT DO NOT FEED in this situation.
If you decide to ride the serpent - let the light be of, do not stress the fish and try to lower the temperature below 25 degree C, run your skimmer with as much air as possible - without skimmer cup if necessary in order to get as much air as possible - and
do not feed. If your pH will get lower - it is good - the toxic amount of NH3 will be lower. Much air can rise your pH but in this case - the NH3 must come out. If you do not have a skimmer - let your outlet of your filter make as large surface movement as possible. Its good that you have a foam filter - it will help you in this situation
As long as you test shows NO2 (nitrite) - the NO3 (nitrate) readings is false.
Try to get nitrification bacteria in one or another form and dose every day. When both NH3/NH4 and NO2 are as close as possible to zero - you can star feeding but very, very sparse
Sincerely Lasse
PS - do not feed!!!!!!