Yeah...it's all over the Europe..keeps loosing data signal while voice signal is OK ..(I have 5G version, but I don't have 5g in my area)
I didn't have this problem with S8..
Same issue here on the S20+ (Exynos)
Only "fix" seems to be to change to airplane mode for about 20 seconds and afterwards it works for a limited time. Customer support rep suggested to report this via the Samsung Members app, hope a fix is on the way.