I cannot reproduce any problems at all. Tested placing towers just next to all three types of electric poles, all of them working as intended.
Can you describe more in detail?
1/ Game and mod version.
2/ Type of electric pole. (Small EP, Big EP, Substation, etc.)
3/ Relative position between electric pole and pickup tower.
4/ Any mods that may change the pickup tower. (The blue line of text displayed under the item/entity tooltip.)