I'm in Poland as well and I've been working remotely for over three years. Since the lock down started I feel that everything is a bit slower and less stable, but I haven't experienced major issues during usual work hours doing work-related things (maybe except MS Teams acting up).
However Netflix is broken most of the time during afternoon hours (when I want to keep kids occupied with cartoons for an hour or so to get things done). Luckily other streaming services work fine.
In contrast, my internet connection finally started working great since lockdowns started. I suspect my ISP (small local company in central Poland) got some additional bandwidth or somehow finally fixed their infrastructure when they saw increased internet usage among their clients.
