Just adding this from the post above to make these things clear.
You have to check these arrows
Check the Electrum on the top if it's watch-only or standard wallet pointed by jackg and check the network status at the bottom right corner there is a circle(Red, green or syncing icon).
Also on the addresses tab check if you send the BTC to the right address if you can't find the address that you pasted on Samourai it means that you sent it to the other wallet, not the wallet you currently used(Electrum).
However, if the address where you sent BTC is in the addresses tab on Electrum you might have network issues that is why it doesn't show any transaction in your history tab. So check the network status click it and try to use other servers just right-click and "use as server" and check if it solves your problem. Check the image below as a reference
If it doesn't solve your issue try to change your PC/Laptop DNS
You can use any of these DNS
Google
8.8.8.8
8.8.4.4
Cloudflare
1.1.1.1
1.0.0.1
If the issue is still there copy the address(The address where you sent BTC) and paste it to any explorer to know if that address has a balance.
You can use this
https://blockchair.com/Also, take note of the Electrum version because lower than 3.3.4 is no longer connected to the server, and most of the servers in the old version are under phishing attacks. So you have to check and tell us if what Electrum version you currently use.