SLA for tickets kept on HOLD keeps on changing


We have JSD project where i have mentioned the stop counting SLA while the ticket is kept on hold. However, i see the SLA data in the ticket keeps changing every now and then in the tickets that’s kept on hold. Sometimes it says time to resolution is 1d, and sometimes it says its 8h. There’s no activity as such in the ticket, its just kept on hold.

We are seeing this behaviour since a very long time.

Can someone help me understand why this behavior ?