Past Simple or Past Perfect in the SINCE subordinate clause?

[irmantasgn]

Hello, could anybody help and give some ideas. I would like to find out what tense we use in the subordinate clause with since. Are the following sentences are correct?

1. She had been participating in the programme ever since it started, but last week she quitted.
2. The situation was chaotic. Parents had been withdrawing their children from schools since the epidemic began.
3. I couldn’t wait longer. It had been a whole two hours since he texted me.
4. She was tired. She had been travelling to the city every day since she had moved to the village.
Thank you.

[Joe]

The most correct form is:

1. She had been participating in the programme ever since it HAD started, but last week she QUIT.
2. The situation was chaotic. Parents had been withdrawing their children from schools since the epidemic HAD BEGUN.
3. I couldn’t wait longer. It had been a whole two hours since he HAD texted me.
4. She was tired. She had been travelling to the city every day since she had HAD moved to the village.

However, the use of Past Simple in informal usage is quite common among native speakers.