unix – merging of csv files has changed the date format of date column

I am using a below script to combine several files into one.

awk '(NR == 1) || (FNR > 1)' InterfaceStatistics*.csv > /home/vikrant_singh_rana/nfv/merge/InterfaceStatistics_merge_file.csv

files are getting merged but the date format is being changed.. see column collectTime

circle,collectTime,item,collint,beginTime,duration,endTime,ifIn
Malaysia,20240519131607,PLMN-PLMN/CBIS-A0110PEXP12/COMPUTE
Malaysia,20240519131607,PLMN-PLMN/CBIS-A0110PEXP12/COMPUTE
Malaysia,20240519131607,PLMN-PLMN/CBIS-A0110PEXP12/COMPUTE
Malaysia,20240519131607,PLMN-PLMN/CBIS-A0110PEXP12/COMPUTE
Malaysia,20240519131607,PLMN-PLMN/CBIS-A0110PEXP12/COMPUTE
Malaysia,20240519131607,PLMN-PLMN/CBIS-A0110PEXP12/COMPUTE


circle,collectTime,item,collint,beginTime,duration,endTime,ifIn
Malaysia,2.02405E+13,PLMN-PLMN/CBIS-A0112PEXP12/COMPUTE
Malaysia,2.02405E+13,PLMN-PLMN/CBIS-A0112PEXP12/COMPUTE
Malaysia,2.02405E+13,PLMN-PLMN/CBIS-A0112PEXP12/COMPUTE
Malaysia,2.02405E+13,PLMN-PLMN/CBIS-A0112PEXP12/COMPUTE
Malaysia,2.02405E+13,PLMN-PLMN/CBIS-A0112PEXP12/COMPUTE
Malaysia,2.02405E+13,PLMN-PLMN/CBIS-A0112PEXP12/COMPUTE
Malaysia,2.02405E+13,PLMN-PLMN/CBIS-A0112PEXP15/COMPUTE

Looking for some help to keep the date column format intact.

I am running this script on cloud shell environment.