In a loop while sleeping

Dear doctor,
My father (52 years old) has a recurrent problem while sleeping (3 years with the problem).
The problem is triggered directly by some foods or drinks but other times he says the issue is still there despite of not having taken any of the 'bad' foods (histamine-rich foods like wine or beer, oxalate-rich like sweet potato, pumpkin, quinoa, garbanzos, among others). Some other foods have a much stronger effect and then the problem is from the very starting moment of going to bed (it happens with l-glutamine, whey, collagen, jelly, and more recently with Magnesium Glycinate and Mg Citrate).

The symptom is always the same. The night usually begins well by falling asleep without any problem around 11:30.
Around 4-5am, he discovers that he is sleeping half asleep in a kind of sleep-attempting loop, he sees himself trying to fall into sleep, so he doesn't get to catch up on his sleep, and he bonds with a little groan (like tiny 'umm') that he emits just as he is about to catch up on his sleep, which prevents him from getting out of that loop. The groan is when breathing out and is so low that his wife is not able to hear. In all this time he is as if superficially between sleeping and waking, constantly going in and out. Neither fully awake nor fully asleep. This often happens around 5am and lasts until 7am when the subject disappears and he usually falls asleep. But when he wakes up he has the anxious feeling as being trying to fall asleep in a loop for two hours.
A year and a half ago when he was sent Lachesis Mutus 200ch he was running for a couple of months and then the effect disappeared.
More recently he has tried with Ars Album 3ch, Natrum Phos 30ch and Pulsatilla 30ch with no result. Also tried some months ago with Bovista 200ch with no result.
Personality data: anxious-type person, likes sweets, perfectionist, with good appetite, very thin.

Looking at Remedy Finder looks Lachesis Mutis is very adequate for him, in a higher dillution than 200ch to make permanent the improvement perhaps? But not sure I have made a proper use of the finder facility....
Thanks a lot for your help.
[Edited by ppalma00 on 2020-12-02 13:14:42]