The PKCS12 file could have been created with PBE-SHA1-RC-40, PBE-SHA1-3DES or other encryption algorithms, which are classified as insecure on our devices from firmware version 7.3 and onwards.
https://icom-os.releasenotes.io/release/NuQrd-icom-os-73
Try one of the following solutions:
Export your PKCS12 file and use a more secure algorithm, such as AES-256
If possible, export the individual files (CA, certificate and key)