Probably bit late but best advice is to switch to Duckstation a much newer and better ps1 emulator.
github.com
ePSXe was never updated to be completely compatible with Windows 7 or newer so it probably doesn't work well with DPI scaling plus you'll have easier time centering and cropping the image in Duckstation
GitHub - stenzek/duckstation: Fast PlayStation 1 emulator for x86-64/AArch32/AArch64
Fast PlayStation 1 emulator for x86-64/AArch32/AArch64 - GitHub - stenzek/duckstation: Fast PlayStation 1 emulator for x86-64/AArch32/AArch64

ePSXe was never updated to be completely compatible with Windows 7 or newer so it probably doesn't work well with DPI scaling plus you'll have easier time centering and cropping the image in Duckstation