I state that I have never completed the game in question on Popstarter, but it's strange because no one has ever complained about these problems on this game with Popstarter. Apart from the advice they have already given you and I advise you to follow them too, I will give you other tips that will probably help you solve the problem:
First you need to make sure you have the latest version of Popstarter released (2019/06/05). Another thing you need to know is that most PAL games have a protection called LibCrypt, these protections are often the cause of game freezes. For example, the PAL version of Jackie Chan needs a patch because it freezes at level 4 due to LibCrypt protection. I'm not sure if Resident Evil 2 had this protection, maybe your backup does, search and inquire if you need a patch for the protection. In any case, the combo of compatibility modes 4 + 6 often works wonders on game freezes, try them by inserting them in the cheats file (OPL Manager can help you insert these compatibility modes automatically). Other very important things that can be the cause of your freezes are: a bad game dump and fragmentation. Never underestimate a bad dump, for example I had made a bad dump of Captain Tsubasa which gave me slowdowns during the gameplay as well as the lack of a part of the music and dialogues, the cause was a wrong conversion of the game, because this game had also a .sub file and a .ccd file in addition to the .bin and .cue files, I converted to vcd without giving importance to the ccd and sub files, the latter contains a series of protection information necessary for the game to work correctly, while the ccd is like a .cue file listing all these files including the .sub file. So the secret was to convert the ccd file to bin/cue. And then fragmentation, this plays tricks on game freezes. Perform a full drive format and copy all contents in one go to avoid fragmentation. Also a cluster of 32kb or less is known to cause more fragmentation problems for Popstarter emulated games, format your drive with a 64kb cluster.
The solution is in our recommendations, if not, after making sure that none of this has solved your problem, join the paladins who still keep the PS2 emulation scene alive: Hugopocked and El_Patas. Visit this page for more information:
https://www.psx-place.com/threads/hugopocked-fixes-for-popstarter.39750/
PS. let us know if you fix it