Hi @Mia Zhao MSFT,
Thnx for your Reply,
I tried creating new list from zero (blank List), also from an existing List and from an Excel workbook after exporting. Also I tried from My Lists and Sharepoint List. but the Issue still happens on all places and methods.
I ask for a colleague of my company to try on his end and the Issue happened the same.
Steps I took: (Tried on Chrome and also Edge Browser and Issue happened the same)
1-Go to My List and click on +New List
2-Select +Blank List, add the Name, then click on Create
3-Once in the List, I clicked on the Title Column>Column Settings>Show/Hide Columns>Select ID column checkmark>Apply (to show ID column)
4-Add new Item and the ID will be shown as expected (1)
5-Refresh Browser (F5)
6-Add a new second Item and the ID will be shown wrongly (100000001)

7-Refresh Browser again and the ID will be corrected (2)

Important to mention that I was constantly doing the steps for this last month and the Issue appears since Nov 27th, 2024.
Thanks in advance for your support and I will keep pending on this.