Multiple Case properites (external_id) getting created automatically through Excel Case Import option


We have been reported that there are 4 “external_ids” (“external_id1“ ,“external_id2“,“external_id3“,“external_id4“) case properties appearing in one of the Cases Data Export from our project space named “Block”, where “external_id1“ contain only 1 record as “sultanpur_j“ and other 3 case Properties (“external_id2“,“external_id3“,“external_id4“) having same values stored.

On the above case data, we are using excel import option to upload the cases with having field name "external_id", however internally it got created multiple fields that also create confusions to have multiple case properties of "external_id" referring the excel case Imported file, so do i have anything to be done at my end to get only one case properties as "external_id" ?

Kindly advise.

Thanks and regards,
Gurudayal Sahu