A series of characters with 各 as a phonetic component oddly has 4 different sets of pronunciations in Mandarin. The first set, 格, 閣 and etc. are pronounced as ke, which sounds about the same as 各 aside from some tone differences. The second set, 駱 is read as lou. The third set, such as 落, 酪, 絡, 烙 and etc., often has 2 sets of pronunciations, lou or lau. The last set, 路, 賂, and etc. are read as lu.
In Taiwan 酪 is usually pronounced as luo, so for avocados, instead of lauli like how most say it in China, it’s always just luoli here in Taiwan. The only time people here would default to lau is when they are talking about a kind of cream cheese pudding like dessert, 奶酪, then maybe 60% of Taiwanese people would say nailau.
There is a reason for this. When final stop consonants, -h, -k, -p, -t, etc., that follow an open or mid vowel sound, were lost, the vowel sounds of their character often become au or ou.
The 各 character was originally pronounced more like /kak/ in Old and Middle Chinese. The first sound change was the vowel. It shifted from front to back and raised slightly to become /ɔ/ and /ə/. The -k went through some lenition and became -h in some regions. For example, in Taigi today, the 各 character is pronounced as both koh or kok. Eventually even the -h completely disappeared in some regions. After the final stop is completely lost, that’s when the vowel diphthongnized to au or ou to compensate.
Some regions preferred au and some preferred ou, and Taiwanese Madarin, seems to prefer keeping both au and ou.
Additionally, for characters like 酪, 落, 洛, the initial vowel changed from /k/ to /l/. Another branch of this series kept the initial consonant as /k/ or /g/. These characters, such as 格, 閣 and etc. avoided the vowel changing to au or ou, possibly because the vowel raised higher to a closed vowel like /i/ back in Middle Chinese.
Similar lenition of the final stop consonant leading to a vowel change to au and ou can be found in characters like 覺, 孝, 教, and 國, 博, 桌, 作. Some of the ou changes also eventually dropped the diphthong to become /u/, such as 路, 獨, 度, 毒 and 塑.
In fact, in Taiwanese Mandarin, the change from /ou/ to /u/ for 塑 hasn’t been completed, so some people say soujiao and some say sujiao. The same can be said for 著 zhou and zhao. Basically anytime there’s a heteronym in Mandarin, it’s usually the result of a dropped final stop consonant.
This series of sound changes began pretty early. In Taigi, 著 can be pronounced as tio̍h as well as tiâu depending on the situation. 毒 can be both to̍k and thāu. So it’s not just a Mandarin phenomenon.