VA hiring process

Hello,

Last month I applied at the VA hospital one hour away from me and in different state, anyway I contacted nursing recruiter which she mange to do skype interview with me and another two mangers due to COVID 19 pandemic. My hiring experience looks very different and confusing, in my current job I'm a float nurse and mostly work in the ICU. I did get an offer to work in the VA but they called me three different times telling me that I was selected to be in different unit and finally the called me again and told me that they accepted me in surgical floor, I accepted the offer because it's a good opportunity to work in the VA. The nurse recruiter contacted my mangers for the past 5 years and asked them for reference and she is done with that. Few days after that they send me and email to complete Vetpro and they stated that they're expediting the process due to covid 19 and I completed that in the same day and when I looked at it the next day morning everything was verified including references and education and everything else, the next day they sent me tentative offer in their ICU. I'm so confused about the whole process, is it normal for them to call my mangers and ask them to be my reference? I submitted the same info over an over again and also completed the nursing dimensions like weeks ago and the nursing boarding. How long usually it takes in situations like these to give me the firm offer?