I used to be Pastel first line support 18 years ago (did it for almost 10 years) - so it was a long time ago and things have moved on a lot I'm sure. I'll share of my experiences, maybe there is something here that can help you.
Back then there were no cloud solutions etc so Pastel ran on a local machine. If you wanted to have more than one Pastel users access the same company, you needed to buy a multi-user licence which allowed the database to to updated with transactions that are sent from other network computers. The one PC is then set-up as a "server" and on the other PC's you map a network drive to this server and these PC's then read and write the data directly to the company file on the server.
There was a massive issue with the Realtek drivers that certain network cards used back then which sent incomplete info to the Pervasive server file. I spent plenty of time changing network cards at clients to attempt to solve the issue. Pervasive back then was pretty bad as well as it the DB allowed partial records with no parity checksums to ensure complete updates of the DB tables. So if there was a power dip for instance during the time a workstation user saved a transaction, the debits will be stored but the credits not. That resulted in your trial balance going out of balance and I had to take out my trusty version of Smitware DDF builder to insert a manual one-sided entry. It was fun and games I tell you. If the server is also a workstation that is under heavy use, it places strain in the DB further. Moving the Pastel company to a dedicated server does help to some extent.
I will never run Pastel on a DB such as Access where a network is involved, more so where POS is in the mix and you have high volume data flow.
Pastel POS function was pretty poor back then - more of an afterthought than anything else, not sure if it has improved.