InDesign IDLK (InDesign Lock File) problems

Hi

We (at work) have just upgraded to InDesign CC 2017. Our setup is like this: couple of Mac's (creative) and a couple of PC's (copywriter).

Until CC 2015 the IDLK (InDesign Lock File) prevented "the opponent" to enter the InDesign doc. while is was open by anyone in the Mac/PC combined workspace.

In CC2017 my Mac can't see PC generated IDLK file and PC can't see Mac generated IDLK.

It means that, while I working in a InDesign doc., my colleague can open the same doc at the same time... it courses at lost of trouble!!!

Now what??? any ideas?

Best Regards

Reno